Wikipedia is a "fluid" resource, as it is constantly being updated and edited by its users. There is no way to verify users' credentials or authority on a subject. Wikipedia can be a good starting point, depending upon your topic and/or your level of knowledge, but users must employ a healthy degree of skepticism and conduct additional research to verify information.
Following are some external links, including tips for for evaluating Wikipedia articles, using Wikipedia information, and source reliability, to help you make your decision:
Again, please keep in mind that while it's not a good idea to cite Wikipedia as a source itself, it can sometimes be a helpful starting point. Don't forget to look at the References, Notes, Sources and Further Reading, and External Links sections of Wikipedia articles at the bottom of each entry, as these can often provide a lot of good information. For instance, look at the entry for technology. Scroll to the very bottom of the page to consult the sources Wikipedia cites in this article, as well as their suggestions for further reading.