I personally like Ernie Ball Earthwood Light Gauge Strings, 11-52. They sound good, and are around $5.00 a set. as for Nylon strings. You will need a classical guitar to use them properly, they will not go on a guitar made for steel strings.When you play a classical guitar, you will be fingerpicking to play it properly. Martin makes a string with a nylon core inside the steel, they are easier on the fingers.