This is what I do:
Change my settings to lossless; Rip CD's (usually, a batch at a time); Change my options to lossy (specifically, MP3, 228? something VBR); Select all the Apple Lossless files I just generated (sort by Date Added makes it easy, as long as I'm not doing anything else with iTunes, which I have to admit, I've done once or thrice); Right-click -> create MP3 version; Profit!
I actually keep them in two separate folders, too, but that also requires me to stop the thing when I hit "okay" after changing my settings.
Let me know if you need more detail, or if that helps. Bitrate is up to you -- I started out lossless, then went to 320, then went to where I am now -- and that's sufficient. This is mostly for car listening, so my requirements are even lower than yours, but I have it set higher than I can hear by a goodly margin.