I\'m a C# developer and I have to change my display resolution regularly.
There are plenty of examples on how to read the current display resolutions: SystemInformation.
I also recommend that you check out Jared Parsons PInvoke Toolkit. You can download it here:
http://www.codeplex.com/clrinterop/Release/ProjectReleases.aspx?ReleaseId=14120
It makes adding pinvoke signatures to your code a breeze. It doesn't always pick the right interop types, but it's usually pretty close, and even if you have to make some changes its still usually quicker than translating everything by hand.