Buy the FasTest Master Kit. It does ammonia, nitrites, nitrates, and pH. It costs around 50 up front, but the refills are less than 10. The kit is reliable, easy to use, and accurate enough for a cycling tank, and the basics. I have used this kit from day one and I am very pleased with it.
A lot of people will reccomend salifert, and I agree that these are great kits. More accurate, but for the basics, accuracy is not neccessary. (well except for pH) If you can detect anything as far as ammonia, or nitrites are concerned, then there is a problem. The salifert kits are twice as expensive as the FasTest and they are not refillable. Go with FasTest