One option is to surf the college math department pages for their postings of old exam and HW assignments - usually under the appro- piate class page. I found some excellent notes, problems and solutions in group theory. What's interesting is to compare what the different departments are doing that term - what text is being used, why (why some aren't - opinions can be strong) scope of the course, etc.
As for books, Schaum's Outline on Linear Algebra is an excellent source of elementary problems and solutions. There are many texts on linear algebra (too many in fact) each with it particular bias (either matrix aggebra, vector spaces, or numerical linear algebra). Some elementary ones are by Anton, O'Nan, and Banchoff.