1) How poor do you get?
That depends on how you approach the situation. I came out money ahead but I'd already paid my mortgage off, made $30k during my 2L clerkship, moved some friends in leech a little rent and defray the monthly expenses, and started a business with one of my law profs who took it upon himself to pay my tuition.
Since you have a technical background you have another option: the US patent office is hiring *tons* of new examiners right now. You don't need any training or experience, just a technical degree. They're begging for forlks with degrees in EE, CSE, CS, & life sciences, less so for MEs but it's still a viable option. You'd spend the next 4 years tormenting lawyers making 4x+ what you'd be making then graduate with your JD and enough experience in a relevant field to open doors that would otherwise be initially closed (e.g., corporate counsel slots where they typically want 4-5 years of experience). Besides, DC, despite being a cesspool, is a rockin' town and just happens to have a higher concentration of law firms starting assoicates at $100k+ than anywhere else in the nation. If you want to be a lawyer, that's Mecca for you.
2) How long does it take?
Three years full time with summers off or four years of night school if you're working full-time. If you're interested in the part-time option be sure the colleges you apply to offer it, some don't. Most programs will have an option that allows you to load up in the summers and get out a semester early. A better option for you given your interests might be one of the few joint JD / MBA programs, those usually require 4 years.
3) Do you like being a lawyer?
It beats engineering but I was looking for independence more than anything else. I'm perfectly willing to succeed or fail on my own merits but I'm unwilling to slave away in a large organization will find the first excuse to show me the door when I become overly expensive (read "hit about 50"). As one of my previous managers used to say, "Engineering is a young man's game, law is an old man's game." There's a lot of truth in that.
4) Random things you should know.
Law schools are regional - State bar concerns aside, law is a *very* regional profession. If you don't attend a top-10 type of program or graduate cum laude (or better) with a law review credential, plan on an uphill battle in any early attempts to leave the area in which you attend law school. Having a tech background mitigates this a bit as does having some work experience.
Attend the best law school that will have you - At least apply to the top 10-15. I don't care how far in debt you have to go or how much you despise the parts of the country in which those programs are located, those are the only ones that will almost certainly pay for themselves in short order. Additionally, Rusty - middle of the road Harvard JD is going to make partner at a large national firm every time while Rusty - top 20% ku law grad and law review editor is going to lose out to the average grad of the better program every time. Performance is king but in this profession pedigree is equally important, moreso if you intend to secure the higher-paying positions.
Understand the economics - Financially this is a pretty straightforward profession. The key factor in the longevity of your position is how much income you generate for the firm. The average large firm (where the money is) operates at about 50% overhead, that is to say that overhead consumes 50% of collections. Perhaps less in second cities, more if they have the top few floors of the Sears Tower or the like. You also must, of course, pay your own salary and benefits (rule of thumb for benes is 1/3 of salary) and, most importantly, kick in cash for the partners to take home. E.g., the firm I was with in LA started attorneys at $130k. Rule of thumb says add $42k for benefits. Add another $172k for overhead and the break-even money to have me there was about $350k. Of course if they're paying me $130k I'd damn well better be putting at least half that much in the partner's kitty, with overhead that's another $130k I need to generate to make keeping me around an attractive proposition. Thus if my goal was to stick around beyond the first year I needed to generate a bare minimum of $480k in revenue. Our first year associates were billed out at $185/hour so that's roughly 2600 hours billed and collected. That firm had a partnership structure that didn't penalize partners for carrying deadbeat clients so collections were only about 90% of billings which bumps the hours worked requirement up to just under 2900. Of course no one is 100% efficient in their work (there's always non-billable time as well), how much slop there is depends on a lot of factors but figure no better than 20% for a new grad and usually not much worse than 10% for someone who's been around a couple of years. Figuring 20% slop, your first year would now be required to work about 3600 hours in order for the firm's billings and collections to show that he's worthy of sticking around another year. Assuming you take your two weeks vacation like everyone else that's about 72 hours/week. Keep in mind that's the *minimum* that will be expected in that environment, if you want to make partner you'll need to be in the top 20% or so of all associates in collections (5% at some firms) and have devloped a knack for generating business. I normally worked 70-80 at my pre-law school corporate job and did 60/week on top of being a full time student all the way through law school so for me being at a big firm was like a vacation. My peers however didn't share my enthusiasm for the relatively short work weeks, YMMV.
Don't believe the hype - The only places paying $180k to new associates are probably small litigation boutiques with stunning client rosters. Those positions exist with about the same frequency as powerball jackpot winners which is to say that they're out there but don't expect to find one and don't use that as any kind of actual upper bound. To get a slot like that you'd better be a 6' blonde olympic swimmer who's drop-dead gorgeous, has massive hooters, gives great head (and like older men, lots of older men), and who also happens to have graduated #1 in her class at Harvard Law. If you don't believe those first few criteria make a difference I can give you the number of the chick in my law school class who appeared in Playboy, slept with most of the local NBA & NFL teams, graduated in the bottom 20% of our class, and got a $120k/year job right after we finished ... in the worst legal job market wince WW II. Or the former model who got in a couple of years behind me because she included her swimsuit shots with her application , transcripts showing way below average grades, and low LSAT score; the prof heading up the admissions committee (himself having been suspended for a few years for sexually harassing a female student) took one look at the photos, tossed the rest of the application in the trash, and put her on the admit list. Even the $100k+ jobs for new grads are relatively rare (figure 10% of all new grads, far less from lower tier schools). Salaries are somewhat proportional to the regional cost of living, the $130k jobs are in places like LA, NoCal, NYC, DC, etc. where the cost of living will take the money right back out of your bank account. Of course you can always go from biglaw in NYC to KC or Omaha but doing the reverse is very difficult. Probably the best deal financially would be to set up shop in a small town in the midwest where homes are dirt cheap. A few years down the road you could easily be pulling in 6 figures in a bottom 20% cost of living area. I know a guy who stepped out of an exceptional practice and moved waaay back into the mountains out west. He lives in a cabin at the end of many miles of forest service roads but pulls down a half-mil a year running his practice out of his home. He's also obviously an outlier but doing that on a smaller scale is very doable.
I could go on but you get the idea. Barring a ticket to Harverd, Yale, Stanford or the like, if I were you I’d seriously consider trying to get in at the patent office and doing the night school program at George Washington. You’ll come close to breaking even and be far far ahead of your peers when you finish.
