So as a buyer you have an agent yourself who takes you to properties for sale? That's a new concept to me, does the buyer's agent make a commission from the sale? Is it the same agent you're using to sell?
Here, an estate agent sells properties, or manages rented ones, they work entirely for sellers or landlords never for buyers or renters.
Generally speaking, renting is totally separate from buying or selling here. There are agencies that will take a fee from the landlord, and then offer a free service to renters who are looking for a place, and drive them around to look at apartments. I'm not sure if they fee the landlord pays is to list the place with them in the first place, or if the agent just gets a commission when it rents. A lot of people don't bother with that at all, and just look at apartment rental ads themselves. I think that some real estate agencies do handle rentals, but it seems like more of a sideline.
The buyer and seller both have the option of not using an agent, it's not required or anything, but it's highly recommended. So, as a buyer, I have an agent who works strictly for me. We're renting now, but if we were selling our old home and buying a new one, I could use her for both (though, some agents only do one or the other, I think most do both). My agent hooks me up with MLS listings, I go through them and figure out what I want to see (Other agents would do more of that initial research, I'm sure, but I like going through every listing and hand picking places), give her a list of interesting houses, we pick a day when we're all free, and she makes all the appointments. She does that by talking to the seller's agent. Generally, there's a lockbox on the property somewhere, and the seller's agent gives the buyer's agent the code, and you never even see the seller's agent. I haven't gotten past that first step, but I'm sure that if I showed a serious interest, I could request that the seller's agent come to a showing and answer questions.
When you find a house you like, and start the buying process, your agent will recommend the necessary (again, highly recommended, not legally necessary) other folks you need, like a real estate attorney to make sure all the paperwork is in order, and an inspector to make sure there are no hidden problems, as well as a few others (you need someone to handle escrow, and I've probably forgotten a couple people). I haven't gotten this far, but I believe the bank will recommend an appraiser to make sure the home is worth what you're paying. Many agencies will also have a mortgage guy working for them, who will hunt up different mortgages for you. You have the option as a buyer to get your own attorney and inspector, too, instead of using the agency's recommendations.
The seller's agent advertises the property, takes photos, makes sure that it's listed on as many real estate sites as possible, and does the fiddly appointment arranging. If you ask me, it's totally worth every penny of commission to not have to deal with the other agents and make appointments myself. We tried it a few times before we got our agent, and we were lucky if we got a form letter response and got put on their mailing list
The seller's agent also hosts open houses at some properties (I'm looking in a low price range, and don't see many open houses), and again, recommends a real estate lawyer and escrow agent.
The two agents work together to do the negotiating. As a buyer, I'll tell my agent to put in an offer of $X, she'll bring that to the seller's agent, and they'll say yes, or no, or suggest $Y, or possibly something like $X and the seller will pay closing costs (which are usually paid by the buyer). Buyers agent brings it back to the buyer then. My agent can't tell me "bid $X," but she'll do some research and find comparables, houses in the area that are similar and sold recently, and get a good idea of what sort of offer will make sense. I'd assume she could also say "well, you can try that offer, but it'll probably be shot down and not counter-offered" if it was too low, or give specific advice like "there are three other offers on the house, so you need to make a strong offer/offer asking price."
When a house sells, the two agents split the commission 50/50. I'm not sure what would happen if only one party had an agent. If I happened to fall in love with a house that my agent was selling, I could, in theory, go with the dual agency option, in which case the agent would represent me and the seller, but it's really really really not recommended, because there's a huge conflict of interests there, especially since it's in the agent's best interests to get a higher price. Some agents won't do dual agency at all - generally, if you've been working with an agent from a particular agency, she'll recommend a colleague to represent the buyer.