Creative Low-Budget Usability Testing Methods 
Usability testing doesn't come cheap. You can however, follow test models that will help you improve the quality of your products, including websites. Usability professionals agree that some testing is better than none, and traditional formal usability testing can be adapted to fit your needs and your budget. This paper discusses how all four of these methods: low-cost usability testing, heuristic evaluations, expert reviews, and checkpoints in the development process were used to analyze subsites and applications at a federally funded public health website.
Reilly, Maggie T. and Cathy N. Hogan. STC Proceedings (2005). Articles>Usability>Testing>Methods