Hi,
I've install the multimenu module. It's very great and useful module. From the installation, there are totally 6 blocks, 1 2 3 4 and A B. There is the admin UI for manage the content of menu 1 to 4 but I couldn't find how to change the content of menu A and B. In other word, I also not understand from the readme file that say "you have now 2 "free" blocks wich you can use to select any category links."

Anyone please suggest
Thanks so much

menuA and menuB are not independent menus, they just link to the menu that you specified (menu1 to menu4). You will find them useful when you need to display the same menu on 2 places, i.e. right block on one page and left block on another page.