I'll confuse the OP and say CVS should be your first choice. Reasons follow

• For me, CVS is much simpler and more intuitive than Subversion.
• CVS is much more mature, with a wider body of knowledge and experience. If your having a problem, your more likely to find a CVS person to help than a Subversion person. This will, of course, change over time.
• CVS is available by default on a lot more systems than Subversion - generally you'll have to install and configure Subversion, CVS will probably be there. Again this will change over time
• In my experience, renaming files, ala Subversion, isnt that common an operation. Of course if your work requires constant renaming, Subversion becomes a more attractive option. That said, when more extensive versioning features (say like ClearCase - expensive but feature-rich) are available, it does open whole new worlds of dev/build/release options
• more tools integrate back to CVS than Subversion (at present - again this is a moving target)
• If you start your introduction of version control with CVS, I'm pretty sure 100% of your versioning needs will be met for quite some time. By the time you realise CVS isnt all you want, you will be better armed to know what you need from a versioning tool. If that new tool is Subversion, it offers migration tools (and most version control suites offer cvs2xxx-like tools)