Location of RPM database files:

/var/lib/rpm/

To install a package (i=install v=verbose h=show hash marks):

rpm -ivh package.rpm

To uninstall (erase) a package:

rpm -e package-name

To upgrade a package:

rpm -Uvh package.rpm

To test a package without installing (checks dependencies):

rpm -Uvh --test package.rpm

To verify a package:

rpm -Vvv package-name

To verify ALL installed packages:

rpm -Va

To find installed package names matching a pattern:

rpm -qa | grep pattern

To see what files a new package is going to install:

rpm -qpl package.rpm

To see what files belong to an installed package:

rpm -ql package-name

To see what package owns a file:

rpm -qf filename

To rebuild the RPM database:

rpm --rebuilddb

To bypass running the install/uninstall scripts in a package:

rpm -ivh --no-scripts package.rpm
also
rpm -e --no-scripts package-name

Mass install:

rpm -ivh *.rpm

Mass uninstall of packages that match a pattern:

rpm -qa | grep pattern | xargs rpm -e