It's easy to transfer them.
Download the MP3 files to your laptop/PC, launch Itunes, find the folder with the MP3 files and let Itunes load them in (or just select all of the files in a window and drag them to the iTunes icon. It "should" add the tags (artists name, track name etc.) if iTunes is set to download the information. Once that's done connect your iPad and sync. You should see the iPad show up as a connected device on the left, find your music, playlist or individual tracks, select them and then click "APPLY" at the bottom.