One of my best ways testing this is to go to news.mobile.msn.com, then scroll down and click the mail icon on the left. Although the sign in says Windows Live (if using a browser that is not supported well or if your browser is basic, or Microsoft Account, just sign in using your Microsoft account ID.
|I hosted this image on imgur this time, because|
SkyDrive was giving me issues for some reason.
Once you are signed in, you'll see the mobile interface. It is fairly easy to use, and I've also noticed that even the mobile version of Outlook now enforces the HTTPS settings that you have on your account, because previously you wouldn't have HTTPS email if your browser "does not support HTTPS (an example is the PlayStation Portable's web browser, and it does support HTTPS)". This is probably because the interface didn't know what browser you were using.
Using the mobile interface is really easy; once you sign in, you are taken to your inbox. And note, I am using Apple Safari for this via changing my user agent settings to mobile Safari to fool Outlook into giving me the mobile interface instead of the PC interface.
To make a new email message, click the plus button to the right. To view your folders, click the "Outlook folders" link. For more stuff, click the "<<" going back beyond the folders.
Hope this has helped you a little bit. If you haven't seen my in depth look, you can by clicking the "Outlook.com Coverage" link on the page bar. That will probably be there until the end of the preview phase or a little after the official launch.