Like many reference works, Wikipedia may be an excellent source for...
Familiarity - if need to become more familiar with a topic or need a starting point for research
Terms - if you're struggling to come up with search terms or keywords for your topic
However, there are common reasons why your professor may not let you use Wikipedia as a source:
Wikipedia is a general encyclopedia or reference work. At the university level, your professors are looking for more than general rudimentary material. General encyclopedias give baseline information, oftentimes it's the type of common knowledge that isn't usually cited. Academic, subject-specific encyclopedias will often provide more scholarly and citeable information.
There is often difficult, at best, to determine who edited an entry or their level of expertise in the subject.
You cannot be sure the content is "permanent", although you can look at the revision history.
Determining the academic rigor of the content is difficult. One of Wikipedia's main principles is that it strives for a neutral point of view. The problem is that in any knowledge endeavor, much less a collaborative and ad hoc venture like Wikipedia, deciding what's neutral and having something reviewed for this neutral point of view can be controversial and too uncertain to meet academic standards.
For ideas on how to use Wikipedia more effectively, visit the Using Wikipedia guide by University of Pittsburgh.
Instead of Wikipedia, try...
Use the library's catalog - Engine Orange. Some topics will have a "research starter", generated by our subscription databases, which can also serve as a reference work to gather research ideas.
Use SHSU's Reference Databases. FYI: If you're off-campus you will be prompted to enter your user name/password. We recommend you log into Blackboard or MySam prior to starting your search.
Explore Reference Universe. Search a selection of print and electronic encyclopedias, dictionaries, and other Reference books.