I'm thinking about getting a Nikon slr digital camera, But I don't know what kind?

Nikon camera.

An entry-level model, such as the D3200 w/ an 18-55 kit lens is a good starting point.

BUT if you just want a nice camera to show off to your friends and show off on tumblr, you don't need a DSLR. If you actually plan on learning about photography, then sure, buy one.

Nikon brand is good but if I were you I will choose the Micro four thirds camera. They has the same quality like SLR camera and they are lighter and has many specifications like the art features and different menu to choose from.

I have an Olympus pen ep3 and I don't regret from buying it.