Does the Nikon D3100 SLR have manual aperture, shutter speed, and focus?

Does the Nikon D3100 SLR have manual aperture, shutter speed, and focus?

Yes, on the PMAS dial

Yes it does

All Nikon dSLR cameras can be shot in the fully manual mode

Yes, it does.

Yes.

This video tutorial will help you learn about your Nikon D3100:
http://www.nikondigitutor.com/eng/d3100/index.html Who better than Nikon to teach you all about your Nikon DSLR?

Its also a good idea to read & study the Owner's Manual for your camera and lens. Make sure you understand how to set your lens for manual focus.

Also, if you're interested in shooting in Manual you'll need to understand the Exposure Triangle which consists of Aperture, ISO and Shutter Speed. This site explains it:
http://www.digital-photography-school.com/learning-exposure-in-digital-photography

Sounds like you're looking for a DSLR suited for a photography class. If so, then the Nikon D3100, as are all DSLR's (not bridge cameras), will have full manual aperture, shutter speed, and focus options. Every Nikon, Canon, Pentax, Sony, and other DSLR's have aperture, shutterspeed, and programed auto modes. The mid-level and novice models also have several scene modes for typical shots such as action, portrait, etc.

Here's a full 20-page review for further information.
http://www.dpreview.com/...ikond3100/