Nikon D3100 shutter/exposure time?

I'm am looking to get a new camera sometime soon but i need it to have adjustable exposure/shutter speed. I'm am looking at the nikon D3100 at amazon.
here is the link
http://www.amazon.com/...003ZYF3LO/
i just need some help figuring out if this does have adjustable exposure/shutter speed (i'm pretty sure that's the same thing basically) i no most digital cameras have this but i just want to make sure before i buy it.

also i'm probably going to need to find a shutter release because if it is only a fifteen second shutter time i will need more time, so if i can get help finding one that is compatible with the Nikon d3100 that would be cool.

All DSLRs have adjustable exposure.

The D3100 is a decent entry level camera. And yes, you can put it on full manual.

You have complete control over the exposure. You can adjust the shutter speed, aperture, and ISO.

For a remote, you can use Nikon's MC-DC2 wired remote. There are third party wired remotes which cost less. BTW, the slowest timed shutter speed for the D3100 is 30 seconds, not 15. You can read about this in the manual which is on Nikon's web site.

It is a fully adjustable dSLR with interchangeable lenses.

You have total control over what it does and if you like, you can shoot in RAW and keep the cameras processing away from your images.

The specifications show the D3100 to have shutter speeds from 1/4000th second to 30 seconds. If you need longer exposures, you put the camera in the Bulb setting, lock open the shutter with a remote shutter release and use a timer or your watch