From the Help section in Outlook:

To add an e-mail or newsgroup account

You will need the following information from your Internet service provider (ISP) or local area network (LAN) administrator:

For e-mail accounts, you'll need to know the type of e-mail server you use (POP3, IMAP, or HTTP), your account name and password, the name of the incoming e-mail server and, for POP3 and IMAP, the name of an outgoing e-mail server.
For a newsgroup account, you'll need to know the name of the news server you want to connect to and, if required, your account name and password.
On the Tools menu, click Accounts.
In the Internet Accounts dialog box, click Add.
Select either Mail or News to open the Internet Connection Wizard, and then follow the instructions to establish a connection with an e-mail or news server. "

If you are adding hotmail accounts it is miles easier. Just follow the same instructions but you don't need all the info about mail servers etc - Outlook does it for you. Basically just go through the add account process for each hotmail account, entering each hotmail email address and the relevant password.