You can use anything that looks good on your quilt. It depends on how much you want it to show. If you don't want it to show, but sink into the fabric, go with a 50 or 60 wt. thread. If you want it to show more, go with a heavier one. I have used all the different kinds that everyone has been talking about. I even have used serger thread, with no problems. Even after the quilt is done.
I prefer to use one thread in the top and Bottom Line in the bobbin. I have even used Bottom Line in both the top and bobbin.
If you are just starting out, I would say to start with a finer thread and then move on to others.
Like someone else said, try different threads on a couple of quilt sandwiches. Mark on them what they are. When you see something you like - go for it.
Good luck! Oh, one more thing, be sure to practice on the sandwiches first, before you do your quilt. Relax and enjoy the learning process.