yeah, the free version of softimage does leave a water mark sadly
the best site for tuts is DEFINITELY (and believe me, i've searched hard) 3d buzz
http://www.3dbuzz.com
u need to sign up first (its free, dont worry) and then u can download many video tutorials (I hope that u have a fast internet connection otherwise it may take awhile)
they have tuts for all the major 3d packages: max, maya, softimage, lightwave, houdini, etc.
the videos start with the basics, and then get more technical later on. i havent checked out the maya videos yet, but the max ones were very good and it was how i started learning the software.
I hope they can help you out.