Easiest way: Place at least one song DIRECTLY under your music folder and hit "SELECT".
This used to be very easy right up until the option to prevent going "up" from your music folder was put in place. Back then you could simply hit "back" from your music folder then hit "select". Now you'd have to add a line to RR.INI to allow you to do that. Other options are to make a playlist in winamp and load it, or make a browse.rrl link to your music path and hit select on it.
Honestly, I would not encourage anyone to do that, the least amount of songs you load at once, the better for you.