A few years back I was taking a course in the Software Development Life Cycle (SDLC) at the University of Phoenix and at the same time I was also working on developing a formalized life cycle for web projects at work.  Through the course of my research I stumbled across some excellent SDLC templates on the State of Maryland Department of Budget and Management IT site.  How on earth I managed to find my way to this resource is still a mystery by all accounts, but I managed to find it again so I could post it here for your benefit.  With a few changes here and there, you can re-engineer these templates to suit your needs and feel confident that you are doing a thorough job at that.  Enjoy.