To start using TSUBAME2, you must first create an account. See here for how to sign up for accounts.
Many of the services provided here are charged to support their operation, except for some basic free services. To use paid services, you need to sign up for a "TSUBAME group" and buy "TSUBAME points". See here for more details.
With TSUBAME2, we will provide both Linux and Windows based machines. At this time, only Linux-based machines are available for the users, while Windows machines will be provided as virtual machines in the near future.
See here for how to use the Linux-based computing nodes.
Check the user guides page for more information.