Lingering Doubts

I have been trying to push myself to find a new job. I find myself complaining a lot about my current job, so I figured that means it's time to try something new. Yesterday I had a job interview, and I think they may offer me the job, but I am having last minute doubts.

It would certainly be good for me, since I would be in a new environment, meet some new people, learn some new skills, and probably make more money. But I always have that lingering doubt, "What if I don't like it?" My job right now is fine, it's comfortable and I'm well liked, so it would be a shock for me to quit, and I would definately be missed. But I just feel like I'm bored, and I know I need a change of scenery.

The guys who I would be working with if I got this new job seemed pretty cool, my work would definately be tougher, and more high profile, but that's not necessarily a problem. The one thing that bugs me is that the first year, they offer one week paid vacation. How is that possibly enough? I realize that the fact that any paid vacation is offered is more than most, but one week? That seems absurd. That's not even barely enough to go back east to visit my family!

What would you recommend I do? And how much vacation do you get?