Nikon D3100 Self Timer?

I got the camera around Christmas time and still can't figure out how to turn on the self timer! Can anyone tell me how?

Read your manual
it is as simple as a press of a button

Did you actually keep your Owners Manual? If So than why haven't you picked up and STARTED READING YOUR OWNERS MANUAL?
Rule # 1 - Read the Owners Manual
Rule # 2 - Read the Owners Manual
Rule # 3 - Read the Owners Manual
Here's A Hint -
Otherwise You actually would be able to find the Answer to your Question simply by READING YOUR OWNERS MANUAL WHICH THE OWNERS MANUAL DOES EXPLAIN THIS.

Sounds like someone hasn't read the manual yet!
Even without reading the manual, setting up the self-timer should be fairly simple if you have explored your camera in the least bit.
But here is the link to the D3100's manual in PDF format:
http://www.nikonusa.com/...oprint.pdf
Info on the self-timer will be on page 54.