It will most likely install the newer version off the PPA. An easy way to check is to do apt-get install -s codeblocks and see what happens during the simulated install.

Tarballs are a little tricky. I recommend installing build-essential and checkinstall in addition to any dependancies that codeblock needs. Download the tarball, and expand it in a working directory with tar -xf filename.tar.gz. Then read the install file if any for instructions

Typically you need to pull in dependancies - an easy way to do this is to use apt-get build-dep. Then you run ./config (which checks if prerequisites are met and sets system specific stuff), make (which compiles), and make install(which moves the compiled files to the right places). I replace make install with checkinstall to make a deb and install that instead cause its easier to uninstall. YMMV - some applications replace make with cmake and so on.