Porter-Cable is good, solid choice. I use mine frequently in cabinet making, completely pleased with its performance. Researched it thoroughly, and tried it against the DeWalt, and prefer the PC to DeWalt. Numbers refer to the biscuit sizes, from smallest, which are well suited to face frames, through largest sizes, which are used for table top glue-ups and sheet goods.
The PC kit includes two blades that allow you to match the biscuit to the job. Do some online research and ensure this is the joining system you want to use, instead of a Kreg jig for instance, or dowels.
The operator's manual is about average, could be better. It pre-supposes a working knowledge of this type of tool.
Bottom line: Very good tool for the price, and a good means of joining wood when medium strength joints are required.