You're not doing SS but this answers your question anyway:
The first set seems really easy. Should I add more weight for the next few sets?
Nope. If you followed the directions from The First Workout then you started at the right weight. Use this as an opportunity to focus on technique (since you aren't concentrating on muscling up the weight). This early on, technique is your primary goal. Get your lifts perfect and then when your technique is called upon as the only means of moving a heavy load, you'll be right on point. Trust me, it will get plenty heavy soon enough, and when you're under that bar with 2-3 hundred pounds you'll be thankful that you won't have to think so hard about technique, because all you will be thinking is "OHMYGOD-THISIS-HEAVY.
EDIT: Seriously, take this advice. Don't be that guy (or girl in this case) who starts off lifting too heavy and then gets nowhere. Better to start off too light than too heavy.
EDIT EDIT: Or the douchebag who starts off too heavy and then adds weight at the cost of his form by humping the bar and doing quarter squats.