The chart below is a good guide for figuring out the pressures that you would want to set your kegs to in an effort to force carbonate them over about 2 weeks time. This is the low and slow method which works great without risk of over carbonating your beer.
To use the chart figure out what your temperature is in your fridge or keezer, you will see a range of different temps on the left. The numbers along the top are the respected PSIs that you will set your regulator to. The numbers that are highlighted in various colors are your “vols” or volumes. This is something that you will want to research depending on the style you are carbonating.
The key at the bottom should give you a good guide to the various styles and ranges that are acceptable for said styles.
Set your regulator to the pressure that is correct for your desired vols at the temperature your fridge or keezer stays at and give it at a minimum of one week. Two weeks is preferable, at one week you should be able to enjoy, but it may be a bit lacking in carbonation still.
Once you have reached desired carbonation, reduce pressure down to your desired serving pressure and enjoy!