Actually git doesn't work with client-server concept, it is distributed source control, where any repo can act as a remote repo for others and in the same time a local repo.
But in your organization, you need to have a place where you have your code resides either for keep code save, or even to do automated deployment or for any other reason.
suppose you have 2 Linux machines, machine A and machine B. (machine A will act like a server, where machine B will be your development machine)
1. machine A have to have ssh server installed; Login to machine A with user say 'git':
2. go to a directory where you want to keep your code, or even you want to do the autodeployemnt from there
3. init the origin on the server
4. Your server is ready now, Now go to the client machine and create a folder where you will put your development source code:
5. create local git repo and point to the remote server we just created
6. test your installation:
7. that's it, you now can write code and push it to your server, you can add hocks on the server (for deployment) or install your a web server to show the code in fancy interface or support other activities like code-review, etc.