How to use Google Music Beta for Android

Google Music Beta launched, allowing you to upload your entire music library to the cloud. For now, the service is free, and songs you upload can be accessed on any computer or Android device (actually,it's iOS-compatible, too).
Invitations will roll out over the next few weeks, but the Android app is available for download immediately. Here's how to use it:

Use Google Music for Android
Request a Google Music account. You don't need one to use the Android app, but go to music.google.com/music/ and request an invite so you can upload your music library on to Google's servers for mobile access. You'll be able to populate your library through Google's desktop app, Music Manager.
Get the app. Download the Music app from the Android Market. Once installed, select the Google account you'd like to associate with the app--it should be the same one you used to request an invite. The app will pull songs from your internal storage and any music you've uploaded to your Music Beta account (requires an invite).
Play music. Tap a song to play it, or hit the arrow to the right of any song and select Play. Shuffle and repeat options can be found in the "now playing" screen, while skipping, playing, and pausing are always available in the bottom bar.
Make an Instant Mix. Tap the arrow to the right of any song and select "Make an Instant Mix." Google will automatically create a playlist with similar songs in your library.
Create a playlist. Select the arrow next to a song, artist, or album and select "Add to Playlist." You can add the music to an existing playlist, or create a new one.
Listen when you're offline. In the Artists, Albums, or Playlists tab, press the Android menu button (on your phone) and select "Make available offline." Tap the pushpins next to the items you want to listen to when you're not connected to Wi-Fi or your cellular network. Hit "Done," and the music will be cached onto your phone. You can deselect the pushpins later to remove the songs from your device.
Tip: To monitor the progress of your downloads, go to Settings > Download Queue. The number of songs you can download for offline listening is based on your device storage capacity.