IPod Illiterate, Please help?

I'm looking to buy an Ipod. I know nothing about Ipod and I can really use some advice (the apple website doesn't really help me) I would like something simple and not too pricey, I just want an easy Ipod that can hold about 3,000 to 4,000 songs. I will probably purchase through ebay, are there Accessories that it should come with? (ex. charger? case?) Thank you!