There is a collection of some amazing 6502-based projects on the web built by fellow enthusiasts on the 6502.org website here. Many of the sites listed on 6502.org offer schematics, source code, and even photos!
If you know of a self-built 6502 system on the web that is not listed here please send us the URL via email to 6502.org. Also, 6502.org offers free web hosting for sites with good 6502 content, just ask if you’d like to take advantage of this service.