I have to second the TurboTax nomination. I use them every year, have for 6 or 7 years now. Their setup takes you through the entire thing, covers all the bases, prints out all the forms already filled out for you for your records, efiles, saves your information in their online vault and lets you import your info next year to save time. I pay em an extra 20 bucks each year and they guarantee me audit protection too. I figure with all the moving around I've done and as screwed up as my records get sometimes, its worth it to have some help if the IRS ever comes after me.
On top of that, they get me more back than a live tax preparer has ever done.