How to take video in NIKON D5100? - 1

How to take video in NIKON D5100?

Read the manual:
http://cdn-10.nikon-cdn.com/pdf/manuals/dslr/D5100RM_EN.pdf

Shooting movies starts on page 107. Reading the rest of the manual will be useful, too - if you are using the video portion, remember this is not a camcorder, but a dSLR designed to capture still images, The section on using Live View and overheating causing auto shutdown is on page 105; maximum video length (4 gig) is on page 108; recording internal noise when using the built-in mics is on page 109.

This is not to say the D5100 can't capture good video - it can, but it is not a camcorder, can't be treated as a camcorder replacement - and you need workarounds for so pretty key issues.