i too started with a mr beer kit. if you follow the directions, it will make decent beer. so yes it's a great intro to homebrewing.
if you continue with this hobby tho you will definetly outgrow mr. beer fast.
i say do a couple of brews with mr beer. if youlike the results and wish to continue consider stepping up to atleast a true brew kit:
available at most lbhs.
good luck with your brew and continue the tradition of homebrewing!