The problem is that people pretty much do what they want here, you can try to get people to enforce the laws but usually you just had to take what comes. But I will answer your questions as to what generally happens although no guarantees.

Agent fees: you might have to pay a small upfront fee to get the agent to even work with you. Not all charge it though.
Deposit: Usually 1 month rent... We paid 1 month deposit when we first moved into our flat, then the building changed landlords and the original landlord disappeared with our deposit (so we'll never see it again). At least the new landlord didn't require a deposit when we signed with him.
Payments: You give the landlord postdated checks for the agreed upon length of the lease (1-2 years). Then he deposits one per month. You might have to pay a year in advance, but that's usually for the higher end places.

There is a place to go to if you have a disagreement with your landlord. Hopefully you won't need it. If you do, do a search of this site and there are plenty of discussions about it.

Good luck! Rumor is that rents are going down. We shall see.