We get asked this a lot so hopefully this will help and please feel free to continue asking at any time. We are always happy to help.

The Beginner Player
Typically you will want to buy a lighter gauge string set. The reason is to reduce the pressure your fingers have to endure while you are building up callouses (or tougher skin at least). If you are learning the guitar AND have to also deal with the discomfort of finger tip pain, then the guitar will give you grief and while are learning, you need to make it as easy as realistically possible. Lighter gauge strings will help do this as they are thinner.

Tone is directly associated with string gauge but as a beginner, you don't need to worry about that. Just worry about making your instrument as comfortable as possible while you try and learn it's mysteries.

If you are learning on an electric, then we recommend 09-42 Lights or even 08-38 Super Light sets.
If you are learning on acoustic (better option), then we recommend 10-46 Extra Lights. 28-43 if you are playing a nylon string guitar.

Also if you are studying with a teacher, make sure to ask he/she about your string gauges. Any good teacher will be keen to help you with this.

Please let us know if you would like any more specific information added and happy playing!