It sounds like you are in the stock recovery not CWM, you have to flash CWM to flash a rom.
I would also suggest not using rom manager to flash roms. I've seen many times where rom manager messes up when flashing a rom and softbricks a phone. I would use rom manager to flash CWM then use the reboot in recovery option within rom manager first make a backup then choose the options to wipe data/factory reset, wipe cache partition, (under advanced) wipe dalvik cache, (under mounts and storage) wipe system, then choose the install zip from SD card, navigate to the rom and flash it then reboot.