Hello,
A lot of what you will need will depend on how large your shop is, and where it is located. Signage, advertising, and different licenses and permits, come into play. Where my shop is located, there were a lot of town permits needed, such as from the health district, and the building permits. (I even had to get a special exemption from the town to install a barberpole, because in the town where my shop is, they have a regulation that states there are no rotating signs allowed!!)These can get costly. Also if you plan to sell any items, you should look into a "sales and use permit" All towns and states have different rules guiding them, and so I think that it would be a good idea to meet with a town official, before you go to much further.
As far as employee's go, I choose to pay them by commission, that way if the shop has a slow day, I won't be paying them more than I can afford. The more experience a person has that works for me, the higher I pay them in commission. It is well worth the money to have someone that is experienced, if someone with a lack of experience gives one bad haircut, your reputation could be damaged. I consider them not only employees, but also friends.
Good luck with your shop!
Brownstonebarbers