Cool. I used to make paper models with my kids. This is one of the best sites for nice free models. Check out the cat on the front page. No I didn't make it I did make several others though.
The free models link is near the bottom of the page.
EDIT: I seem to remember having to download a language pack for acrobat reader or many of the pdf didn't have correct characters.
PS I can recommend the Orca whale as easy but very impressive, It's in the free animals section.
also there's this "pepakura designer" program (if i remember the name correctly).
basicly it's a simple 3d modeler but it can print your models in this format. so you cut them and make real paper models from them.