First you should look around, you might find a ppa having the new version. That is the easiest way.
In the case there isn't:
Building and installing software from source can lead to messed up libraries or binaries on the system, as another package might overwrite something or vice-versa.
To avoid this, there are 2 solutions:
- Only build the source, and use the binaries locally, but this means
you have to write your own init or upstart service for it, if you
want to handle them properly.
- In my opinion the best: Get the repository version of source code with apt-get source, overwrite it with the new source, and build it the debian way. There is a quite good tutorial on package building here. The only drawback is, if there is some change in the building process, you have to make the changes in the debian scripts too.
You should also consider, that a new version might depend on a newer library than your repository has. In this case you might find a ppa of a newer build, or you should build one yourself with the same way, but this can be a quite long process, walking through all the dependencies.
In short, if you are luck you may get through this fairly quick and easy. If you are not, then you are better using your distro's version.