To install the latest version of a package:
yum install <package name>

To search for a package:
yum search <package name>

To find what package installs a program:
yum whatprovides </path/to/program>

To find the dependencies of a package:
yum deplist <package name>

To find information about an installed package:
yum info <package name>

List currently enabled repositories:
yum repolist

To download the source RPM for a package:
yumdownloader --source <package name>

(You have to install yumdownloader first, which is installed by the
yum-utils package)