Just a few tips:
1- It's safest to only flash a recovery while booted into the OS, and only flash an OS while booted into recovery. LeslieAnn explains it the best, the idea being that so long as one is working, you can always fix the other. This means the flashable recovery zip files are not really a good idea.
2-flashgui is a good tool, but it actually takes longer to use than just typing in the commands in terminal:
Code:
su
flash_image recovery /sdcard/NAME_OF_RECOVERY_HERE
reboot recovery
3-if you have troubles with your normal sdcard partition not showing files, and the unmount/mount trick doesn't help, try putting the file on the sd-ext partition, mount it, and you should be able to see it no matter what (providing the recovery supports your ext type)