I would start here:
http://www.ni.com/pdf/manuals/372668d.pdf
This is a LabVIEW guide for FIRST robotics (a little old but mostly still good). Chapter 38 will cover solenoids etc.
You can also go to Help>Find Examples and you will find a couple of relevant examples.
If you have specific questions we can answer them.
Worst case come find me during Bayou on Thursday and I'd be happy to help I will be around one of teams 1304,4805, or 4113.