Adding Cydia Repos

Adding new sources for iPhone software packages in Cydia makes it possible to take advantage of what independent developers have to offer on their repositories. As long as your iPhone is Jailbroken with Cydia installed you can add a repo by following these instructions:

1. Open Cydia and navigate to the Manage tab
2. Touch Sources to reveal the current list of repositories.
3. Tap the Edit button in the upper right hand corner of the screen.
4. Enter the repository URL exactly as it appears and select Add Source.
5. Wait a moment while your iPhone downloads releases and packages. When the process is complete press Return to Cydia.
6. Now you can browse the packages offered by the new repository by navigating to Manage -> Sources and touching the repository name.

Source: www.iphonefaq.org/archives/971440

Installing a Tweak

1) Refresh your sources with selecting the "Changes" tab in the bottom
2)Open or search a preferred tweak, press "Install" or "modify" 
3)Press "Confirm" and let Cydia do the rest of the work
4)After its done you press "Return to Cydia" "Restart Springboard" or "Reboot"
5)DONE! Enjoy the new tweak!
NOTE: If you experience problems you can simply uninstall the tweak you recently installed to fix the problem
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Editing Repos

  1. Click on the repo
  2. Press Edit on the top left of the screen
  3. Flip the switch of things you don't want to show up when you refresh your sources
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