I recently decided to try out EGit, a GIT client plugin-for Eclipse. Following are the steps I took to get it running in Eclipse-Helios.
Step 1: In Eclipse go to Help --> Eclipse Marketplace
Step 2: In the wizard that pops up, highlight "Eclipse Marketplace" and click Next.
Step 3: Search for "git". On the top of the list, EGit showed up for me.
Step 4: Click Install and wait while it calculates requirements and dependencies. Click "Next".
Step 5: Accept the terms and conditions and click "Finish". Choose to restart Eclipse after the install finishes.
Step 6: Window --> Show View --> Other...
Step 7: Find and choose the Git View under Git > Git Repositories.
Now you should have your Git view and you can start using Git from within Eclipse!
Piece of Cake!!!