An excellent source for TSBs is the Nissanhelp web site (Link). Put your mouse pointer over "Ownership" and click on "Service Bulletins," then follow the links. You must be registered to view or download TSBs, and you can only download 1 file per day with a free registration. If you pay the $10/year subscription fee, you can download as many files per day as you want.
Service manuals are also available. You can only download complete manuals (all sections) if you have a paid subscription, but individual sections can be downloaded free. If the section you want isn't shown, ask the moderator to upload it.