A workbench needs to be heavy enough that it doesn't move under you while you're working, and stiff enough that it doesn't rack itself to pieces under the forces that will be placed upon it. It doesn't take many hours of planing a board or hammering a chisel for a worktable made of nailed 2x4s to come apart. Traditional bench designs use mortise-and-tenon joinery, which is strong and rigid, but not really suited for a novice woodworker who doesn't already have a bench.
Put the upper panel of MDF on your glue-up surface, bottom side up. Put the bottom panel of MDF on your other surface, bottom side down. (The panel with the holes drilled in it is the bottom panel, and the side that has the your layout diagram on it is the bottom side.) Chuck up in your drill the appropriate driver bit for the screws your using. Make sure you have a freshly-charged battery, and crank the speed down and the torque way down. You don't want to over-tighten the screws, MDF strips easily.
Projects to build on. Korn's book includes basic projects that you can put your own spin on. This Shaker footstool was inspired by one of the projects in his book. The last side-table project in his book (pictured) has the same pedigree as these two other FW projects: Tim Rousseau's small cherry cabinet and Stephen Hammer's small stand with coopered panels.
I marked the holes by putting a dowel center in the end of a long piece of 1" dowel. Run it through the holes in the base plate, and bang on its end with a mallet. Rotate it a bit and bang it again, and repeat. Odds are the dowel center won't be precisely in the center of the dowel, so you'll be making a small ring of marks. The center of the hole is, of course, the center of that ring.
Thread the rods through one of the legs, then set the leg flat on the table. Insert dowels into the dowel holes. Place the matching stretchers into place. Put dowels into the dowel holes at the top end of the stretchers. Place the other leg onto the threaded rod and settle it down onto the dowels. You'll probably have another opportunity to whack away with your rubber mallet.
@cahudson42 I bored the holes in my sandwich top with a 3/4" power auger bit with the drill in a portable drill guide that kept it vertical and in a way a bit like a plunge router. The guide screw of the auger was dead easy to centre over the laid out grid points. The holes are dead straight and clean sided. The auger bit was new which probably helped. As stated I have three rows from an end vise running the length of the front as well as from the front vise and holes in the front apron to support long pieces as well.
2. Bill Hylton's Power-Tool Joinery by Bill Hylton. From the editors of Popular Woodworking magazine, this is a go-to for setting up power tools for making joinery. Organized by joint type - rabbets, half-laps, dovetails, etc - it provides detailed instructions show you how to make each joint with every tool possible. I especially like the jigs and fixtures details that show you there's definitely more than one way to skin that cat.
One quality about this bench that is definitely lacking is space – both tabletop and storage. The Olympia Tools does provide an adequate shelf, but it does not come with any drawers, nor does it offer the option of adding them later. The table top is the smallest we saw at 50” long and 2’ wide, though the width is actually better than most of the other table we reviewed. Still, a significant chunk of that width is occupied by a trough. This trough is designed to hold smaller workpieces to keep them from falling or getting knocked over, but it removes about 6” of width from the tabletop.
“Woodworking in Estonia” by A. Viires (National Technical Information Service). This is our share of the booty from the cultural exchanges of the Cold War years. The Soviets got models of our nuclear subs, and we got one of the best books on folk woodworking ever. Aside from showing how to make everything from wooden wheels to bentwood cheese boxes, this book is also an education in the way Eastern European history gets written. Imagine Eric Sloane dividing early American woodworking into feudal, capitalist and socialist periods!
One you have the vise jaws shaped so that the vise moves freely, mark and drill holes in the fixed jaw for the bolts that will hold it to the bench. With these drilled, reassemble the vise and mark the location of the holes with an awl. Disassemble the vise and drill the holes through the stretcher, then reassemble the vise and bolt the inner jaw in place.
I marked out the one hole location, drilled a shallow 1/16" hole into the top. I then put a 1/16" bit through the hole in my template and into the hole I had just drilled. I lined up the template, and drilled a second hole, then put another bit through that. From then on, I worked entirely from the template. With two bits through the holes pinning the template in place, the other holes in the template would be precisely located (or so the theory goes) on a 4x4" grid.
Stop it. Really. I mean it. Pick a height between your thigh and waist that seems right. You’ll adapt. Don’t worry about your back. You’ll adapt. If you are really uncertain, make it a little taller and then cut down the legs. After a decade or so, your work habits will put a magic number in your head. You’ll have built enough furniture that you will know your number. Until then, pick a number.
The hits included Shop Tips, Woodworking: The Right Technique, Router Magic, Woodworker’s Problem Solver and the Woodworker’s Visual Handbook. Each of those books sold more than 100,000 copies because of the quality of the advice and projects. And the books still hold up well, as you can see if you view buyers’ comments on sites like Amazon, where most of the titles consistently receive 5-star ratings.
Assemble the vises, for the final time. You'll not be taking them off again, so tighten everything down, and attach the endplate to the ends of the screw and guide rods. Then mark and drill benchdog holes in the outer jaws inline with the benchdog holes in the top. Generally, through-holes are preferred for benchdogs, so that they don't collect sawdust and gunk. With these vises, that isn't possible, there are screws and guide rods in the way. I drilled them just deep enough to hold a Veritas Bench Pony (their reduced-height benchdog), without it sinking to where I can't get a grip to remove it. Rockler sells some very inexpensive plastic benchdogs that can't be adjusted for height, and aren't as strong as metal or wooden dogs, that I intend to keep in the holes full-time, to keep sawdust from collecting in them.
4. Taunton's Complete Illustrated Guide To Finishing by Jeff Jewitt. This isn't the only book on the subject, but it's a great place to start. The real strength here is the bounty of color photos, which show exactly what's happening as you finalize your projects. It discusses finishing new projects, but also repairing old finishes and matching vintage pieces. It's not a "start here, end there" walk through, so you'll need to familiarize yourself with the way it's organized before beginning a project, but it is indeed a "complete illustrated guide" with encyclopedic-like thoroughness. Belongs in every library. 
Windsor Design is an interesting brand in that it is not actually its own company. Instead, Windsor Design is one of the in-house brands sold by Harbor Freight. While it may be a store brand, that should not dissuade you at all as Harbor Freight is known for selling some of the best products available for all fields of construction. Granted, this may not strictly be the best table available, but it does provide a solid mix of features to make it a good value.