ROS study project

After fall in several pitfalls, I have made an conclusion that is i should clearly think about every possible result no matter bad or good.So before I set up ROS in Ubuntu, Figure out what should i do at every steps is necessary based on the scanning about several essay about similar project.
First 1.1Configure your Ubuntu Respositories
Download the Server
click the software&update button
pick the first four option and then udload the mirror sources
Then click the other sources pick the first option
If you want to see the specific procedure please open the link as follows https://help.ubuntu.com/community/Repositories/Ubuntu
(1) Navigate to Ubuntu Software Centre > Edit > Software Sources > Other Software.
(2) Click Add.
(3) Enter the PPA’s location (as described above).
(4) Click Add Source.
(5) Enter your password. Click Authenticate.
(6) Click Close.
If you are asked if you want to reload the information about available software, click Reload. You have now added the PPA and can install packages from it.
Adding a PPA using the command-line
Make sure you have the package python-software-properties installed.
Step 1: On the PPA’s Launchpad page, look for the heading that reads “Adding this PPA to your system”. Make a note of the PPA’s location, which has the format ppa:user/ppa-name.
Step 2: Open a terminal and enter:
sudo add-apt-repository ppa:user/ppa-name
Replace ‘ppa:user/ppa-name’ with the PPA’s location that you noted above. Your system will now fetch the PPA’s key. This enables your system to verify that the packages in the PPA have not been interfered with since they were built.
Step 3: Now, as a one-off, tell your system to pull down the latest list of software from each archive it knows about, including the PPA you just added:
sudo apt-get update
Now you’re ready to start installing software from the PPA!