First of all, set up the two separate e-mail addresses that you will be using (Tools, E-mail Accounts) Once you have set these up, choose which default address you want to send from. If you set up your personal account as the default, and you want to send using your works address, after clicking on 'New' (for new message) in the top left is an 'accounts' button for you to choose which outgoing mail address you want to use.
For incoming mail, set up two new inboxes, by right-clicking on Inbox - New Folder. You can name these folders as Inbox - Work and Inbox - Personal as an example.
Then, you can define rules for the incoming mail (Tools - Rules and alerts) for each incoming message to be directed to the appropriate folder. The rules wizard is fairly straight forward, but if you get stuck, send me an e-mail.