Strengthen your core first. Don't worry about the vanity muscles, as others have noted. Your tris will get plenty of work on pressing exercises and biceps will also get worked with your back exercises, among others, so don't worry about that right off the bat.
My advice would be to get a trainer (or an experienced lifter) to find YOUR routine and see what works for you, while also having someone there to analyze your form until you get used to doing the exercises right. Then once you're into your routine nice and regular, and you feel your endurance and strength starting to slowly and steadily climb, check out mixing up your routine. The New Encyclopedia has a lot of good exercises in it, along with some decent reading material.
One thing that I've noticed in all my years of lifting and having to train others is that everybody seems to have different routines that work best for them. In the end, you need to safely find out what works best for you, and this may take a while, but once you've figured it out, you'll be impressed with your progress.