http://startingstrength.com/You want to build up to 75% max load, which means if you're doing squats, you do a couple of air squats, then a set with low weight and build up from there.
I do push-ups, pull-ups, etc, but as part of my warm-up, and I don't do them to the point where they become taxing.
If you want to do them as part of your workout, and if you want to do dumbells, or nautilus machines, that's up to you. Just not the most effective way of gaining strength. Other methods are effective, just not as much. Good luck
