The 1st boot after install does take some time, as it has to configure your profile, which includes creating storage directory and so forth. But afterwards it should speed up if not try this:
There's a couple of ways to speed it up, 1st disable the MS start bar if it's loading, remove the MSN messenger from starting as it will open and connect when Outlook opens, as well as the icq bar if installed as well. So by stock if these are all loading you have 3 programs needed access to the net, all opening at the same time, and all trying to connect at the same time.
These are a few things I check for on any new install of Outlook, or office suite