As someone who was once looking to turn pro...
Be very very very sure it's what you want. being a domestic professional cyclist is a hard and thankless job.
Don't expect your career to be like what you see in the protour teams. only the protour squads and the really successful or rich pro-conti teams have the resources to live like that. there are probably only 5 well funded teams in the United states- BMC, garmin ( and their subsidiary, slipstream sports), bontrager livestrong, team type 1 sanofi, united healthcare, and POSSIBLY bissel cycling. the rest more or less live hand to mouth. note that radioshack isn't counted as a USA team as they are luxembourg registered. I can't remmeber the name of the magazine, but I think one cycling magazine did a photo article about living as a domestic racer in the US a few months back. it was a really really good piece. for many domestic pros it means living out of a suitcase or a van/pickup truck, eating crappy hotel food after a 5 hour race, washing your own jerseys to prep for the next days stage after killing yourself. no soigneurs or chefs.
I'm assuming you're aiming to be a continental level racer, or aiming to be pro-continental.
unless you know someone, you're most likely starting out at continental level. most continental level riders aren't paid, or are paid a pittance. you'll most likely have to have a day job, and have to work your training around that. do note you'll have to train doubly hard and be extra disciplined because you'll be competing against people who DO train full time. I live in asia and a few continental team racers are personal friends. they are bike shops mechanics/coaches/ other day jobs in the day, and they work their training around it. they are very very very disciplined people. Even so, alot of US domestic teams are at the mercy of race orgnisers since they arent really big- see what happened to kenda 5-hour this year.
if you do make it to a major conti squad that travels around racing (e.g. kelly benefits, exergy, kenda 5 hour, competitive cyclist, et al) it will be difficult to have any sort of social life with people who aren't fellow cyclists/team mates. you'll be constantly travelling during race season. you'll miss birthdays, weddings, thanksgivings. when you're home, you'll most likely be training or resting while your friends are at work. during winter, holidays and Christmas you will be watching your diet and preparing for the next spring/summer races. be very sure this is something you can be okay with. because it could mean breakups and the end of friendships also. not saying it WILL happen, but it is a possibility.
I'm not trying to be a bummer. If you're really serious about this, chapeau to you. to me, when I weighed the cost of a normal social life with friends and family against continuing trying to go pro, it wasn't worth it. but be very sure this is the path you want to take and you are prepared for what may happen.
If you are set on this path, I'd agree with what people said about getting to know some people. for every aspiring neo-pro that makes a pro-conti squad, there are at least 5 equally or more talented riders out there who just didn't have the contacts to get in. I would take a look at the current roster of professional cycling outfits in the USA and have a plan as to which you think you could probably get in. seek to make friends with some of them at races, make it known you are a good rider, and maybe they'll put in a good word for you. Slipstream sports and bontrager-livestrong are probably out for you, sicne you're abit old to be on a development squad. but the others are all distinct possibilities, if you're good enough.
I second on having a plan B. wish you all the best and hope you do make it big.