If you're using Pro Tools to create your tracks, just follow the directions below to export them as 320 kbps MP3 files.
When you're ready to export in Pro Tools, click File at the top of the page, then select Bounce to > Disk. When you do that, the Bounce window will appear. In the Bounce window, find the:
File Type drop-down menu and select MP3.
Format drop-down menu and select Interleaved.
Sample Rate drop-down menu and select 44.1 kHz.
Conversion options check boxes and select Convert After Bounce
Once those selections are all set, click Bounce at the bottom of the window. When you do that, a new MP3 metadata window will appear. In the Encoder section at the top of that window, find the:
Constant Bit Rate (CBR) drop-down menu and select 320kbit/s.
Encoding Speed drop-down menu and select Slowest (the slower speed will provide a higher quality file).
In that same MP3 metadata window, you can also edit your track's ID3 tag information. Once you have all of that information filled out, click OK at the bottom of the window. After clicking OK, you'll be able to choose where on your device you'd like to save the files. Be sure to click Save once you've selected your download location.
After clicking Save, a pop-up will appear that tells you how much time is remaining until your track will be done exporting. When that's done, your 320 kbps MP3 will be all set on your device and ready to upload to Digital DJ Pool :)