Stop worrying, fleece is easy to work with! It doesn't ravel; in fact, you can cut and use it for a, say, blanket and not have to finish the edges. Fleece is a bit harder on needles but an 80/12 or similar will work just fine if you do want to finish the edges or work with it.
It also will not shrink so no pre-washing is needed except, where it jwill keep it's size, and you want to use it as a quilt backing, you might want to pre-wash any fabric that isn't fleece.
Fleece, although light weight, is very warm. We don't use top sheets anymore, just a single fleece blanket, all year round.
For more information about fleece, and to find bargains, check out this store that is an outlet for Polar Fleece from Malden Mills:
http://www.milldirecttextiles.com/