I think you have the order a little mixed up. These are the steps I would take:
1) Establish a buyers list:
A) Network with investors at your local Real Estate Investors Club.
B) Call "For Rent" ads and signs and talk to the landlords who may be buyers for more properties.
Now you will have an "order list" and can go out and seek properties that fit their parameters (area, price, type of house, whatever).
2) As a bird-dog you will have an agreement with the buyer that if you bring a deal sheet to them, which fits their criteria for buying, they will pay you a finders fee or bird-dog fee if they buy it. Then you would be out of the picture and on to the next search.
3) As a wholesaler you would write a purchase agreement up, make an offer and get your offer accepted in writing by the seller. Then you would contact the investors on your buyers list and pitch your deal and see if they are interested in buying it. You will add your assignment fee to the price you are asking from the investor-end buyer. This fee can vary a lot, from $2K on up. If he accepts, he closes the deal with his financing and you get your fee (or some wholesalers get their fee up front).
4) Establish a marketing plan to find/obtain motivated sellers.
5) At this point it is your job to match the sellers with your buyers.
All the info above was pulled directly from Mike's post. I'm sure Mike will chime in if I missed a step or has further advice.
Thanks