Can someone help me ... do I need bitinstant before opening up an account with mt.gox?
nop. you can just open an account, and for example sell bitcoins.
if you wanna buy bitcoins, you have first pay money on your mt.gox account. for that are many possibilities (even bank transfer) to get your money on mt.gox.
with bitinstant it would be the "fast" way. but in the moment it does not seem to be "fast".