To search the online help files, from the Help tab shown in the following screenshot, choose Help Topics, or press F1 from anywhere in SDL Trados Studio:
The Help ribbon also gives access to Tutorials (instruction videos on SDL's YouTube site) and SDL Knowledge Base (a repository of answers to technical queries), and several other resources such as SDL My Account and Product Activation.
In the Welcome view, the information tabs in the middle of the screen also provide quick access to various helpful resources as follows:
GET STARTED: This tab has a number of quick start guides and how-to videos
MORE RESOURCES: This tab gives access to release notes, the migration guide, and so on
LATEST NEWS: This tab provides information from SDL on the latest bug fixes, updates, and so on
You can also look for help and ideas in independent resources such as ProZ.com (the SDL Trados support forum) at http://tinyurl.com/proz-trados. The blog by SDL's Paul Filkin includes lots of useful articles on SDL Trados Studio and related topics (see http://multifarious.filkin.com/).