Oracle have published the entire Siebel documentation set which is now freely available here .
This means that technical staff no longer need an account on Siebel SupportWeb to access the Siebel documentation. Siebel Bookshelf, for all versions (6.x, 7.x and 8.0), may be viewed online and can also be downloaded locally (HTML format) for reference.
The Siebel documentation is also available for download from SupportWeb in PDF format which allows searching.
Another useful tip for people with access to SupportWeb is to subscribe to the weekly newsletter published by Technical Support. This email typically includes details of relevant changes (updates to Bookshelf and Systems Requirements & Supported Platforms, availability of new Maintenance Releases, breaking Alerts or recently added TechNotes).
For example, TechNote 688 'Siebel 8.0 Simplified Demonstration Installation Tasks for Windows' contains a useful potted summary of the prerequisites and basic steps for installing Siebel 8.0 on Windows.