Another option that I am currently researching is leasing an employee! You do the hiring and a third party company does all of the IRS, Federal, and state requirements. All you do is pay that company along with their fees. You get to be in complete control without all of the headaches. The employee is yours full time and you don't have to keep re-training.
Staffing Agencies: a good option when you don't need a full time employee but there is no guarantee that you will get the same person each time (double check that - I am not an expert). If they quit the agency, you lose.
Sub-Contractor: be careful... this is an IRS red flag! If they get to set their own schedule and use their own tools along with a number of other rules, they might be a sub-contractor.
Good Luck
Leasing an employee in California requires that you have your own Workers Comp. These companies usually charge you for every little thing - per check, child support, W2's, etc. So know what you get upfront.
As for Staffing Agencies. Well, I do consider myself an expert (owner 10 years).
If this is the way you maybe considering you should try to find a locally owned one. Find out how long they have been in the business. Then tell them what you want. Ex. I want the same person everyday not a new guy every other day/week.
When you get the employee he/she is yours to supervise. Talk to the employee first, find out what they are looking for short term, long term, seasonal, part time, full time.
We do all the interviews first then let our customers choose to do there own or not. A lot of our customers have been with us since we started. We have a great relationship and they just call and tell us to send someone as we already know them and what they need/like or maybe even ask if someone who has already worked for them is available.
They can also have them back ground checked (if your going to a customers home this is a good idea to have this done, Could become a liability if something comes up missing). Drug testing, pre employment, random, accident.
I'm not saying this is the only way to go but in my 10 years I have seen A LOT of things go wrong for owners that don't understand all the Laws/Rules of the game. Let me tell you this the rules are always changing!! Miss a payment to the IRS and well it will cost you more than you made with that employee.
You are getting A LOT of advise on here and I'm only trying to get you thinking about what is my best way to start my business safely for your own future. Trust me when I say if you make a bad choice and down the road you are doing well, then get a big fat bill from the IRS or an AUDIT you aren't expecting, it's not very fun.
One more word of advice from experience. As an employee you think one way as an owner you'll think a whole different way. After all you are the one that took the chance.
Employees are your best friend until something goes wrong then it's all about what can they get you for. Let me say, this is NOT every employee. We have worked with and still have many GREAT employee's, but can you tell me which one is and isn't this way by looking at them? We haven't figured this one out yet. So be careful however you choose to pay them. Always protect your self. C.Y.A. was made up for a reason.
Starting a new business is fun and exciting, but we don't always think about what if something happens until it happens.