To transfer things to, and to run things on the n900:
Just use root@YOURPHONESIPNUM, where YOURPHONESIPNUM is your phone’s ip number.
– To run python scripts on the n900, type “python SCRIPTNAME” where SCRIPTNAME is the name of the python script you would like to run.
It might be more convenient to do command line things, on the n900, from a laptop/desktop, via ssh. To log into the n900, from a different computer, open the terminal window and type “ssh root@YOURPHONESIPNUM”, replacing YOURPHONESIPNUM with your phone’s IP number.