It is better to choose one with a higher class number. Class 4 to 10 have been working allright for me so far. It should be at least with 4 GB capacity. Try to find a proper SD card for the job. This is were we will install the Operating system for the Pi. We need an ethernet port, and the model A doesn't have one. This guide is a combination of information found on the internet and experience. A fast way to setup Raspberry Pi with Raspbian.