Tire pressure is always a big subject of discussion, but checking tire pressure accurately is very important. You want to buy the best gauge that you can reasonably afford. Dial type gauges usually give the most accurate readings. The pocket clip pencil type will give you relative pressure readings but are not known to be very accurate. The digital are better but from what I have read about them they may not be highly accurate either, plus they have batteries that may go dead at the wrong time. A good dial type gauge can run up to $50, but I think you can find good ones for maybe half of that.
In summary, if you are serious about your tire pressure get a good pressure gauge.
In summary, if you are serious about your tire pressure get a good pressure gauge.