The root ( / ) directory needs at least 25 GB of space.
The home ( /home ) directory needs as much space as you will need for your files, music, pictures, and documents. So it is best to use the remaining space for the home partition, unless you are going to have a dual boot.
Swap space of at least half of the available RAM is recommended. For instance, with 8 GB of RAM, you should make the swap have at least 4 GB.
