For continuous testing using Jenkins and Selenium you need to focus on few things -
Use Maven and make sure you have mavensure plugin dependency in pom.xml file. Then upload your code on any VCS like Git or Bitbucket. Now configure Jenkins and use of Git URL of your repository and check on automate build for on every push. By doing above things, whenever you push your code on VCS it automatically start doing testing. Also you can schedule your build.