I have installed Jenkins by deploying its WAR file to Tomcat. On typing
http://localhost:8080/jenkins
In browser
I hate to admit this but it might save someone else some time...I could not find a particular plugin when searching the available list. I learned the hard way that plugins which are already installed to Jenkins don't show in the "available" list...there it was on the "installed" list, already installed, I just didn't realize it. Now I'll check "installed" before searching "available".