Couple of things to tell us that will help a lot. 1) The version of
Ubuntu you are using ( i.e. does it have the side bar of icons ) and
2) The version of Windows that you are trying to access ( i.e. WinXP
or Vista / Win7 ).

Basically you will mount the Windows drive and then you can access all
the folders on it. WinXP holds user data in Documents and Settings
under a folder with the login name, Vista / Win7 holds user data in
Users under a folder with the login name.

Note you will not need any user password to access the files.