some people really love to point out how little everyone around them knows -- don't take the criticism here too personally. The fact that you are going out there and asking for advice is a great start.
I would research extensively about your options out there for gear... I am just starting out and by that I mean, I've been researching for 6 months almost daily. Reading online, forums, you-tube, attending in person classes & seminars, speaking with other photographers. Try and get some 2nd shooting experience in. And try equipment before you buy...
I bought 6 months ago -- I got the T1i -- with the hopes of just learning the ropes with what little money I had to invest. Someday, I would love to call myself a full-time professional photographer, but know that I am not there yet... I love the art of photography and am learning the business... It's not a quick thing that you pick up by shooting one weekend... Most of the important can't miss things I learned from people's hard criticism here on the boards ... it's valuable...
Liability insurance -- get it -- there are lots of places to get that... check out ppa.com // become a member and they also have a company they use to insure them. Or scope out other pro insurance companies (i shopped around) -- it will prob cost you between 300-450/year since you prob don't have much in way of receipts/income for photographer.
Setup an online portfolio to help you spread the word and get some more photo ops. I started doing work for free, but that was a personal choice of mine, I had zero experience in shooting DSLR at the time but had a lot of experience in photoshop -- which came in very handy.
I rented equipment for a wedding. All I owned was a T1i, kit lens, 50mm 1.8, (2) speedlights - 430 + 480. I rented a 70-200mm, 10-22mm (for wide shots) and 2nd camera body. Rent a high end body and try it out -- the difference in quality is noticeable.
I used EVERY LENS... and both bodies.
Lots of SD cards to ensure you don't lose space -- and lots of batteries for the flashes .. I had someone using my 2nd body to help out -- and my 2nd flash -- we went through 24 batteries. We shot EVERYTHING b/c we were overly cautious since it was our first time. We took multiple shots of every pose, sometimes the flash didn't fire or there were blinks or movement..
I also had help -- reached out to a lot of pro-photogs who were more than willing to show me the ropes and give me some advice and a chance. Also now have the opportunity to 2nd shoot, but too bad I didn't have a chance to do that BEFORE shooting my 1st wedding.
Cover yourself... a wedding is something you don't want to be responsible for messing up.
I also had someone come and assist me at the wedding I shot this weekend, just to help upload all the pics we had to a computer and also a 2nd copy on an external HD. I'm paranoid b/c people warned me about the chance of losing images -- that would be horrible!
Make sure you keep in contact with your B&G about what they want, meet with them a week before the wedding...go over details. Have a back up plan for weather...
Get a contract made up and signed... figure out what you want to offer and for how much. Can you deliver?
Try and attend the rehearsal if you get the okay from the B&G -- there you can test out your lighting situation -- the bride gave me print outs of some shots she listed as must-haves. They didn't include formals/family etc... don't assume that b/c they didn't list of give you those, that they don't want them. They will!!
Okay, maybe I rambled on more than you wanted -- Re: what's a good camera and lens to use.
Hope this helps a little bit... it's a lot and overwhelming in the beginning ... and still is for me as I'm still learning. I take every opportunity I can to learn!!