I recently got a r4i SDHC and a 2G SD card. Since its my first time using them, can someone please tell me how to use them properly (or give me a link of a guide)? also, how do we download musics on the sd card? whenever i try to, it says something like ``cannot find any music (compatible AAC files)``. What is this AAC thing?
*This final question isnt really important, but it would be great if someone answers it. So i heard there are many types of R4i. Can someone tell me the difference between R4i SDHC, R4i ultra, R4i Revolution, and so on? thanks a bunch!