On PCs, tablets and smart-phones you can easily access TeX manuals and documentation via a web site: TeXdoc.net.
What does it provide?
- Keyword search with auto-completion as you type, listing all matches
- OpenSearch for browsers with a search engine toolbar
- Documentation sorted in categories by topic
- Accessing TeX documentation even without having TeX installed
- Reading TeX documentation on any PDF capable device with a web browser, such as a smart-phone.
- Newest documentation even if your PC has an older TeX version
- Reading a package manual before installing it
- Easy-to-remember standardized link syntax http://texdoc.net/pkg/<packagename>
- Forums, such as LaTeX-Community.org and goLaTeX.de have buttons and BBCode tags for linking keywords (package names) to the corresponding documentation
Recently it got an update: read more.