If you want to search loads (and I do mean LOADS) of free (and also not-free) patterns for knitting (and crochet) -- you need to become a member of Ravelry
It is an online community for knitters and crocheters. The patterns section is absolutely amazing, and easy to search. For example, if you knew what you wanted to make (like a rug), you could search for rugs. Then you could filter that search to narrow down the results even more -- say, using the particular type yarn you have. OR you could start a search based on the type of yarn you have and how much of it you have to see what kinds of things you could make from it. The site is virus free, and while Rav does link to free patterns on peoples' blogs off-site, they are legitimate links and legitimate sites that they are linking to, so I'd not worry about getting a virus that way. Go check it out and sign up!
ETA: I'd also recommend installing a good anti-virus software -- not that I'm worried personally about Ravelry, but just in general it's a good idea. You never know!