Olympia Tools is a bit of a lesser known manufacturer. While they offer a wide range of products for a variety of construction fields, they are definitely more of a budget option. That said, Olympia Tools is one of the few brands that manages to produce a reasonable quality at a low price which makes them a solid choice for customers looking to get the best bang for the fewest bucks.
I agree that even at 12x12, things'll be "cozy" inside. That's OK. Keep in mind that this will be a general purpose hobby shed, not just a wood working shed. Even 12x8 would be plenty big enough for building 1 meter wingspan bungee launched RC gliders. And for the electronics projects I do, I only need enough workbench space to do some soldering with a 3rd hand (for electric guitar pedals). If I need more room than the shed offers for wood working projects, I'll just roll the table saw down a ramp and do my cutting outside in the sun.

In this two day class we will reveal some of the secrets to tuning up a Japanese Hand Plane (Kanna) We will start with conditioning the Body of the Plane (DAI) to stabilize movement. Proper sharpening and grinding of the blade and chip breaker will be discussed and demonstrated. Custom fitting the blade to the Dai and conditioning the sole. We will...
For one, the bench itself is a good size. While its width as a tad short at just over 1 ½’, the length is a great 5’ long. Even better, this bench is made out of birch wood. Birchwood is similar to beech in that it is strong but soft enough to prevent inadvertent dulling of your tools. However, birch has a bit of an advantage over beech in that it is not a porous which makes staining on the Windsor Design a more worry-free affair.
This trade and technical college currently serves over 15,500 credit students from its campus in downtown Los Angeles. Through the Construction, Design and Manufacturing Department, full-time students can enroll in a daytime certificate or an Associate of Science program in cabinet and millwork. Evening programs for current craftspeople include a certificate program in construction technologies and an Associate of Arts in cabinetmaking and millwork that provide students with the skills they need to work in construction or manufacturing.
If you opt for a bench with drawers or cabinets built into its base, don’t forget the toe spaces: Leave a space roughly three inches deep and four inches wide at floor level for your toes, just like kitchen cabinets. The absence of a toe space means you’ll be forever kicking the face or sides of the cabinets which is irksome and, with tools in hand, potentially dangerous. And you’ll have to lean over farther to reach the back of the benchtop.
We have more than sixty years of excellence (1956-present) with an annual enrollment of more than 1,000 students in over 35 different classes.  The Palomar College Cabinet and Furniture Technology program offers the most comprehensive woodworking career curriculum in the nation. Utilizing three fully-equipped shops, our 2 full-time and 20 part-time instructors provide a breadth of courses and depth of expertise impossible to obtain in smaller programs.
The next day, cut it flush. Use a block plane to ensure it truly is flush. This will be the top of the bottom layer of the bench top, so gouges aren't a problem. (Wiping up glue with a damp cloth can lead to stains and finishes applying unevenly. That won't be a problem here, either.) But bulges and bumps are a problem - they will keep the two layers of the top from matching up evenly.
Workbenches have flat tops, though sometimes at the rear there is a cavity called a tool well that contains tools and components (and prevents them from falling off). One advantage of having the well set into the top of the bench is that, even with a variety of objects in the well, a large sheet of material can still be laid flat over the entire surface of the bench; the contents of the tool well offer no interference.

You may even want to put yourself in the picture. If your workshop space already exists, find a large piece of cardboard, wallboard, or plywood that’s about the size of the workbench top you envision. Find a couple of stools or chairs, perhaps a few books, and turn them into stanchions to support the “benchtop.” Is it too big for the space? Is it large enough for the tasks you envision will be performed upon it?
This is definitely going to be one of the easiest woodworking projects you’ll be reading about today. So why not just get started? The tutorial link is given below. Just do exactly what they are saying in the tutorial and you will end up making a beautiful wooden doormat just like the one in the image above. They are using pine wood to build this doormat. You can choose any wood material that best suits your budget.
I decided to make my own top out of white ash because I had access to a planer and jointer at my local college where I was taking an intro woodworking class. Trim and vice jaws are white ash as well. Everything else is built pretty much as jdege describes. A plunge router with a 3/4" spiral up bit really made quick work of the dog holes. Finished with Danish oil.
Regardless of which type of screw you use, you'll need to flip the panel and use a countersink drill to on all of the exit holes. Drilling MDF leaves bumps, the countersink bit will remove them, and will create a little bit of space for material drawn up by the screw from the second sheet of MDF. You want to remove anything that might keep the two panels from mating up flat. I set a block plane to a very shallow bite and ran it over what was left of the bumps and over the edges. The edges of MDF can be bulged by by sawing or just by handling, and you want to knock that down.
Synopsis: No room in the garage? Basement not an option? Consider what Ken St. Onge did when he needed shop space: He bought a prefabricated shed and converted it into his full-time woodshop. Because a pre-built shed doesn’t need a cement foundation and is built in a factory, it’s much less expensive than building an addition or stand-alone shop on your property. It can have taller ceilings than a garage and bigger doors than a basement, both big pluses for a woodworker. You can put a shed just about anywhere, too. Here’s a soup to nuts look at Ken’s experience, so you can gauge whether a shop in a shed is right for you.