For a very first step I would say get a real estate agent and start making offers based on the equation I gave you above. And here is what you say to your real estate agent. "Hello my name is ____. I am an investor and my strategy is to buy, fix and sell a property where I can turn a $20,000 to $25,000 profit. I am looking to be in and out of deals quick." I use this script even if fix and flipping isn't my strategy because most real estate agents don't want to work with wholesalers because they don't know what they're doing or want them to show 20 houses and offer half price on twelve of them. However if you know what you are doing and don't jerk them around you can so many deals with an agent that they don't want to work with anyone else. If they are skeptical then move on to the next realtor. Once you get one that is neutral or says "I can help you make more" then you ask your general questions. Where are the hot spots? Where are the investors making money (zip code ect.)? What price range of houses is the hottest selling right now? Once you've built a bit a rapport you want to get some listings to review. What I ask for is "starter homes" (these are different for every area but are generally 3 bed 2 bath and the price can vary wildly but in my area its around $100k) listed as-is, vacant, and/or has had a price reduction. All of those things indicate a motivated seller which is what you need if you are going to be buying at a discount. I also ask them to pull a list of the "cash solds" for the past 90 days in the area you are going to be working in (your realtor can do this in the MLS don't believe them if they say they can't) Once you have done that you can do two things.
First start building your buyers list by taking that list of cash solds and opening up your county website somewhere on there you should be able to look up tax records. Then go through you list of cash solds and seach each property on the county website by the lot #, parcel #, or address (whatever your county website uses). On the tax page for every property you'll see the property address and the tax mailing address if they don't match you can bet that that is an investment property and you'll record the tax mailing address and any other relevant info. This is the start of your buyers list. That combined with going to my local REI club was how I got enough cash buyers to start wholesaling but there are literally hundreds of ways to grow your buyers list. How you don't grow your buyers list is by buying some list online (the 100 contacts for $19.99 crap).
Second start making offers on houses. side note: I think of this in to categories MLS deals and non-MLS deals. My ratio is roughly 60:40. Your realtor gets paid their commission from MLS deal but I work out a flat fee with mine for the non-MLS deals but there are many other ways to do it. But since we're breaking in a new realtor we will stick to MLS deals. What I do (this is the way that I do it there are many other ways) is look at all of the deals that come through the search that my realtor set up and if a property meets my criteria I will take the asking price times a multiplier. This is my truncated way of doing my equation above so that I can be the first on these deals in the MLS. I use between .6 and .9 for my market. Right now I am using .73 but that is after lots of deals. That is my offer price, I will then send my realtor all of the offers that I am going to make (this happens every day with the new set of properties emailed to me). I adjust my multiplier so that I get a property accepted per number of offers (~40 if you only want the big deals and less if you want more deals). Once a deal gets accepted the key to making this work is have your realtor make 2 changes to the contract one have some sort of escape clause (ie. contingent upon partner approval) and have at least a 7-10 day "inspection period" so that you can go in and have your realtor run the comps you can get a rehab estimate from a contractor, take pictures, run the real numbers (the full equation) and make sure that this is a profitable property. Do not dawdle on this i try to get this done in 3 days so that I have time to market the property to my cash buyers. Once that is all done package it all up in a nicely formatted email and send it out to your buyers and they will run their own numbers and if you did your job right snap it up from you. If you run your numbers and the property doesn't work out that means you need to adjust your multiplier. If your numbers don't work out or you can't find a buyer (which I've never had happen on a good deal) just tell your realtor to drop the deal.
Final note the reason this post is so long and that there are so many opinions on where to start is because real estate and wholesaling especially is a chicken and the egg problem, you need one to get the other. So my best advice is to start I know so many people who psyched themselves out of real estate because they tried to know everything first. If you are really worried you can go to a real estate attorney and pay them ~$300 to write up the purchase agreement with those two changes so that you know it is water tight. After that the worst you can do is upset some people if you have to drop a contract but it is not the end of the world.
