Scotty's right. The compressor will cycle on/off in normal operation, with the exception of when you have the A/C set to MAX. In normal operation, the compressor will cycle when necessary to condense the Freon coolant. In MAX operation, the compressor will run continuously.
The readings you're seeing are correct as well, to a point. As Scotty said, as long as your readings stay within the "acceptable" range on your gauges, you should be fine. It will take some practice to feel fully comfortable with the recharge process, but the simplest way to get used to is is what you're doing. Just charge it slowly, watching your gauges, and take your time.
One other thing, too: your Freon can will chill quickly on the bottom when filling. You'll need to swirl the can around to keep it from freeze-locking, but do not use heat!