Trac
Working with Trac is pretty simple. Any logged in user can create tickets for tasks which need to be done, defects in the code, and possible enhancements. Milestones can be created for intended completion dates, the front wiki area can be edited, and much more.

An excellent user guide is automatically included with the creation of a new Trac environment; you can see it at the wiki page of your project. Additionally, the same guide can be found online here: http://trac.edgewall.org/wiki/TracGuide

Subversion
Subversion is a little more complex, but still remains quite simple. If you are completely new to Version Control Systems (VCS), I would highly recommend looking at this short video (http://www.youtube.com/watch?v=8wYiabh2hpM) as well as this article (http://betterexplained.com/articles/a-visual-guide-to-version-control/). The video offers a great overview of the purpose of version control, while the article goes a little deeper with how the system works.

There is also an excellent guide for how to use TortoiseSVN with your subversion repository. This guide goes into extraordinary depth, and should help you with everything you need to know: http://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-dug.html#tsvn-dug-general.

LabVIEW Users - Read Below
When working with LabVIEW projects in Subversion and TortoiseSVN, there are some things you need to know: 

LabVIEW saves data in binary files, not text. This unfortunately means that the following changes apply:

• There are no nice-looking diffs (file differences). These will not be useful for you, because file differences are no longer line changes, but are instead binary data. Computers won't care that your files are binary and not text, but you won't get anything useful from the differences between revisions anymore. 
  Because of this, writing detailed commit messages is very important. Looking at the log messages may be the only way other members can understand what has been changed between each revision.
• Merging files is more complicated. You must tell TortoiseSVN to use a special tool for merging changes to .vi files.
  This can be easily configured, and a nice guide for how to do so can be found here: http://expressionflow.com/2007/08/28/using-new-labview-merge-tool-lvmerge-with-tortoisesvn/  
  
  Update-3/7/09:  After using Subverison with LabVIEW throughout 2009's build season, it appears that the merge tool provided with LabVIEW will not work, as a license for it is not included in the FIRST software package. However, file conflicts are fairly easy to avoid in small teams (update regularly!), and aren't extremely difficult to resolve by manually comparing files when a conflict occurs. Nevertheless, this remains an inconvenience to consider.