How do i reload my model and weights back into ART

thank you for your response, maybe im not understanding how to save everything properly. am i not only saving the .mb file for maya? i have tried saving characters out in the ART, but i can never seem to load them again. I only have access to the basic Manichean. Example: i have a character that i have done half the weight painting. when i reload that .mb file to work on, i cant access the ART for that character. It only lets me make a new rig, or load a character (aka: The Mannichean). Im probably just missing something easy. thanks for you help!