Search and install
yaourt [keywords]: quick search + install
yaourt -S [packages] : install package, Compile it from AUR if needed
yaourt -Ss [keywords] : search on repos and on AUR (with notice for already installed packages)
yaourt -Sb [packages] : install a packages by compilation from sources (abs)
yaourt -Sl [repos] : prompt for packages of the selected repos (emphasize those already installed)
yaourt -Qs [keywords] : colorized ouput of installed packages and the repos where they come from
yaourt -Qo [progname] or [filename] : shows the package which provides the program or the file

Updgrade:
yaourt -Syu : complete update and upgrade of the system (onlys from repos)
yaourt -Syu –aur : complete update and upgrade, even for packages coming from AUR
yaourt -Sybu –aur : complete update and upgrade by compilation of all packages (repos and AUR)
yaourt -Su –devel : update and upgrade of cvs/svn/mercurial/git packages

Cleaning:
yaourt -C : editing and merging of .pacnew/.pacsave
yaourt -Cc : removal of all .pacnew/.pacsave
yaourt -Qt : search for orphaned packages
yaourt -Cd : search for obsolete repos

Other options:
–export [directory] : exports compiled packages for gensync
yaourt -S –aur [packages] : forces compilation from AUR for a packages which is also in repos
yaourt -G [packages] : retrive PKGBUILD and local sources in current directory.
yaourt -B : backup the pacman database

Tux Training » Blog Archive » How to install and use Yaourt in Arch Linux