Just drag and drop the EverythingPvP.jar and a copy of Vault into your /plugins folder. Then restart or reload your server and you're good to go! (When downloading EverythingPvP, the changelog will tell you what Vault version you need!)
If one of your plugins installed is conflicting with EverythingPvP then send me a ticket including the conflicting plugin's name and version, your EverythingPvP version, and your Craftbukkit Build Number. If you have found a bug, send me a ticket including the server log, and screenshots if necessary. Please do not report bugs or conflicts in the comments!