Google Code-in

Find a release that doesn't already exist in MusicBrainz, either one you have yourself or one that's downloadable for free online (ask your mentors, they can help you find one if you can't).

Then you should do the following things:

1. (Optional, if it's a CD you have.) Rip the CD using a good CD ripper, e.g., EAC on Windows (also runs under Wine on Linux), XLD on Mac OS X, or morituri on Linux.
2. Add it to MusicBrainz - be sure to enter all information you know/can find, incl. status, release date and country (country will likely be "[Worldwide]" for a lot/most digital releases), label and cat. no. and barcode (these may not be available for digital releases), language and script information, type(s), and packaging ("None" for digital releases).
3. Use MusicBrainz Picard to tag the release.
4. Use Picard to submit AcoustIDs for the files.
5. Download one of the [AcousticBrainz] clients and submit AcousticBrainz analyses for the files.

Post a link to the release here in the task when you've added it so the mentors can verify your work.

If you have any questions along the way, you should join #musicbrainz, the IRC channel for MusicBrainz editors. Even if a mentor isn't around to help you, there are plenty of other people with years and years of experience editing MusicBrainz who are willing to help newbies. Be sure to mention that you're from GCI. :)