If you are a site administrator, you may have users coming to you with troubleshooting questions, or you may run into issues of your own that need to be resolved. You have several troubleshooting options.
What do you want to do?
Find information on Office.com
The Office.com Web site is a great resource for finding information about how to use Project Web App. If users come to you asking about how to use a specific feature, redirecting them to this site is a good first step. If they're unable to find the information that they need, you may have a better understanding of the features they're trying to use, and therefore may be more successful in finding information appropriate to their issue on this site. Regardless, if the question at hand deals with how to use Project Web App, check the Help topics at Office.com first.
Find information on the Project 2010 Solution Center
The Project 2010 Solution Center is the Support Web site where you will find knowledge base articles, links to downloadable content, and other troubleshooting information. If the issue goes beyond understanding how to use Project Web App (for example, if you are encountering an error message), search the Project 2010 Solution Center to see whether information for addressing your issue is published.
Find information on TechNet
The Project Server 2010 TechCenter on TechNet is a great place to look for information about issues that your server administrator might be able to address. If you are dealing with an issue that you think may go beyond the scope of what you control as site administrator, you can search through the content on the Project Server 2010 TechCenter to see whether the issue is something that your server administrator can address.
Post your issue on the Project Server discussion forums
Project has some very active discussion forums, where you can post the issue you're experiencing and see whether any other users have encountered the same situation. If you're unable to figure out the issue by reviewing the information on Office.com, the Project 2010 Solution Center, or the Project Server 2010 TechCenter on TechNet, try posting your question to one of these forums: