I agree with primal rob, especially if you don't have a gym membership, and you are just doing bodyweight stuff, your muscles will be sore but your central nervous system will be less taxed, so you can probably do a couple pull ups and specialized pushups on your off days.
So bodyweight can't effectively tax my CNS enough to take notice?
I forgot images have to be approved
Keep in mind the relationship between intensity and frequency--twice a week can work, but make it really intense. You could also do frequent small sets of pull ups/dips/pushups/squats, just about every day. I need to rest after intense workouts, so I do them 2-3 times a week, but other weeks where I'm working physically or doing frequent lower-intensity (say, one intense set at 3 different times in a day), I'll make it much more frequent. Personally I like to mix it up like that. I guess what I'm saying is...try it and see what works!