Be on the lookout for:

• Dual agency: This means the agent or agents are working on both sides of the fence. For example, an agent with XYZ Realty may represent the seller, while another agent (or the same agent) also with XYZ Realty represents the buyer. There are obviously arguments against this arrangement because of conflicts of interest, but nonetheless, it is still a common practice. In the dual agency situation, both the buyer (you) and the seller must be made aware of the arrangement and privileged information can't be shared unless you agree to it.
• Neglecting to specify: If you begin working with an agent and forget to ask for or sign a buyer's agency agreement then the agent automatically represents the seller. In most cases, the agent will bring this up and offer you the choice. If, however, the agent is the listing agent for a house you are interested in, then the relationship automatically becomes that of a "dual agency."
• Buyer's Agency Clause: One potential problem with signing a buyer's agency agreement may come with a blanket clause stating that the agent gets a commission on any home purchase. If you think it is likely that you will find something without the help of the agent, then you may want to specify in the agreement that a home you find on your own (an FSBO, for example) will not require payment of the standard commission.
• "In-house" Listings: If you're working with a traditional agent (or listing agent) rather than an exclusive buyer's agent, be aware that you might get a little harder sales pitch for their own listings, or the listings held by their brokerage firm, simply because they make more money that way.
• Release Clause: Make sure you have a "release clause" in your buyer's agency agreement just in case you find out you just don't like your agent. This will allow you to sever ties without any future problems. You may need to take advantage of this clause BEFORE you see any houses -- or at least any houses you think you are interested in.