Karen:

M-Box 2 is a great way to enter Protools-
Be forwarned of a long and timely install with Protools M-Box.
This takes HOURS and is a pain -But WORTH IT

If you are going with the M-Box 2 Pro make sure you get the-(I think Digidesign just updated the M Box 2 Pro-look for that one.)
-Digidesign Mbox 2 Factory Bundle Audio/MIDI Interface -
--You get extra plug ins--
Digidesign Mbox 2 Factory Bundle Plug-Ins:
Moogerfooger Analog Delay
JOEMEEK SC2 Compressor
JOEMEEK VC5 Meequalizer
Maxim
Cosmonaut Voice

Take a look into getting a M-Audio 02 for 99 $ or a M-Audio Keystation 49e for the same price.
Here is what I am talking about
http://www.sweetwater.com/store/search.php?s=maudio+midi&tt=1

The BEST place to get Alot and ALL of your questions answered and talk to the same person -EVERYTIME- is Sweetwater.
http://www.sweetwater.com/shop/pro-tools/
1-800-222-4700
Contact name is -Luke- extentsion 1236
I spend hours talking with this guy he is -Cool-
Luke will match prices with anyone and does not mislead you-with ordering and then its on backorder.
I talked with him today and told him (Karen) might be calling-just say Deward told me your # and ext. he will know who you are.
He will be around for about 3 more hours today.

Good Luck in your quest.

Take Care: