The advantage of taking on an apprentice is that they can be taught how to do the work the way you like it done. Any subbies or plasterers you get, if they are good have plenty of work on.
The disadvantage is there are a lot of useless ones that you may have to try before you get a good one.
Stay away from family and friends who's boy/girl is looking for work, if it turns bad it will be all your fault.
You want someone not too bright or too thick , too bright they will be taking work off you in three year time, too thick it will be hard work teaching them.
Go for a long trial period before starting the paper work. Nothing wrong with keeping them on site with you for a year, then if you are both happy, start the apprenticeship.
Don't forget how bad you were when you were 16 years old.
Grant for taking on an apprentice is good but only if you can one that is willing to work.