Welcome to the best forum on the net, i ride a trek 4300 disc same as rec i belive, I love it and i thrash the crap out of mine on and off between commutes and ride that end in "oh look 2 feet of water and mud lets try this" .
As above you need lots of other stuff apart from the bike, honestly if you have any mechanical skills or a wish to learn hit up Craigslist you might fight a hybrid/MTB for cheap but you won't have the support of the LBS .
Let us know how you go, and remember DON'T try an ride 30 miles on the first day , build up your muscles and your endurance small rides each day are fun burning out because you attempted a silly amount is not so much.
anyway,
have fun enjoy your ride and welcome again
Tergal