Looking to build my upper body without spending money at a gym. I am about 60 pounds overweight and have had spinal surgery in '05. I intend on starting a regime of push ups & pull /chin ups but don't know how many reps and sets to start with? OR how many to "step" up to throughout the moths? Would LOVE any advice from you guys to help me build a more  masculine figure.

NOTE** I can currently only do assisted out modified versions of both currently.

I've really liked some websites like... Try googling 100 pushups, 50 pullups, and a 200 situps if that's also something you'd be interested in. They have those words in the URL. I'd link them but not sure if I'm allowed and I'm on my phone right now. I've personally used the push-ups and sit-ups ones for a little while some time ago and found them quite effective, I don't know about others though. I plan on trying the pull-ups one too when I can get a bar.