The Sharkbite fittings form Home Depot work very well with the 1/2" Pex. The special tool mentioned cost $1 it is used to release the fitting should you want to remove it at a later date. That is what I used to install an under sink water filter.
When You do repair as the ones mentioned, You need to go to a RV/mearine place to get the right ones. DO NOT GET THE FITTINGS FROM HOME DEPOT.. They are home fittings.