I see a lot of the same questions repeated (and often with incorrect answers), so here's a short FAQ that may help:
1) How much money can I make mining eth?
It depends on your card and your power costs. As of 2016-08-24, a single AMD R9 380 will make about US$1.50/day, and use 50c/d of power at 10c/kWh.
http://karldiab.com/EthereumMiningCalculator/2) Which miner should I use?
Claymore's and Genoil's are good and work with both Nvidia and AMD GPUs (beginners should try AMD cards).
3) Which pool should I use?
Miningpoolhub is good since it supports vardiff. Pools with a high static difficulty like nanopool are not recommended for beginners.
4) Should I use getwork or stratum?
Only use stratum. If your pool does not support stratum, see question 4.
5) Can I mine with a 2GB card?
Yes, if you set GPU_SINGLE_ALLOC_PERCENT=100. The DAG will be larger than 2GB by February 2017.
