if you are starting from lvl 1 and dont mind forking out the money for more wow+tbc+wotlk for each extra char you add to your boxing..
then i suggest you look into Refer-A-Friend and how it works.

what you pay for for 1 account is 1x wow, 1x tbc (if you wanna go past 60), 1x wotlk (if you wanna go past 70)'

for 2 accounts thats 2wow, 2tbc, 2wotlk
and 3 accounts 3 3 3... you get the picture. i just wanted to make that clear (so many missunderstand that part).
There is several programs that do the same thing.
keyclone, pwnboxer, isboxer or whatever the name is.
there is a long line of names in the wiki .

also just a heads up.
make sure the names of the accounts are the same thing.
not all get banned who doesnt but we all know that a bannstick to your face isnt something we want to risk.
if the accounts arnt give me a poke in private message and il see if i can help you .

good luck and welcome to the fun!