If you go to
www.pinkbike.coom they have a good forum in which they will be able to answer any real technical questions you may have.
That being said make sure that you get a bike that feels right for you and that will mean spending the time at different bike stores, take them out for test rides, see what suspension that you want, if you want a mountain bike or a downhill bike or if a road or a touring bike would work out better for what you need. You can spend your life savings on a bike and have carbon everything, but if the bike isn't what you need and doesn't feel right for your body, then you won't ride it.
Past that, make sure you get some quality biking gloves, a good helmet, nice bike shorts (you can get some which look like normal shorts with a liner built in if you don't want to rock the lycra look) and most importantly bike shoes, and by that I mean learn how to ride with clips, you will likely fall a few times but just try them out on the grass before you head out onto the roads. You will get more power and performance because of greater energy transfer.
If you have any questions I have some family who are bike mechanics and I can get some honest advice for you from someone who knows their stuff and won't be trying to sell you anything... granted most guys who work in bike shops are standup guys who just want you to be happy with what you get.