Hi
How I did it (not sure if it's the best method though)
Create an account at mtgox
Fund the account using a wire transfer (you'll have to wait a couple of days)
Buy bitcoins at mtgox

Create an account at vircurex
Go to the accounts tab
Generate a bitcoin address (BTC = Bitcoin) which will show up in the "deposit" column and is a long string of letters and numbers

Now you go back to mtgox to funding options, go to the "withdraw funds" tab
Choose bitcoins, enter the amount and you BTC address at vircurex
Hit confirm and a little while after you will have your bitcoins at vircurex

At Vircurex you can purchase different altcoins

Hope this helps to get you started