Linseed oil sitting in a bowl, or spread on the surface of wood, is perfectly safe. But a linseed oil soaked rag provides a vastly increase surface area, so the oxidation happens faster, and the rag can provide insulation, trapping the heat. The increased temperature speeds up the oxidation even more, which raises the temperature even more, and the runaway feedback can quickly result in temperatures that will cause the rag to spontaneously burst into flame. This isn't one of those "do not drive car while sunscreen is in place" warnings. This is one of those "keep your finger off the trigger until you have the gun pointed at something you want to shoot" warnings. Rags soaked in linseed oil will catch fire, if you don't handle them properly, and they can do so far more quickly than you might think.
If you're using drywall screws, you'll want to countersink the holes. Drywall screws are flat-head, and need a countersink to seat solidly. If you're using Kreg pocket screws, the way I did, you won't want to counter-sink the holes. Kreg screws are pan-head, and seat just fine against a flat surface. Both drywall screws and Kreg pocket screws are self-threading, so you don't need pilot holes in the second sheet of MDF.
The projects in this course follow a natural progression of skills, techniques and tools. Some of the early student-made tools are, in fact, used to help make the next tool or bench fixture in the series. You are supported in the building of these projects with step-by-step outlines, knock-down examples and continuing, one-on-one consultations with the faculty. Periodic evaluations of your progress with a specific faculty-mentor help keep you on track.

As you can see in the image, this shelf goes on both sides of the corner wall. It looks beautiful and can be used to organize books, trophies, pictures frames and many other things. The strength and design of the shelf depends on how properly you build it. First time workers definitely need some guidance to help them with the process. Therefore, I am including this basic video that I found on YouTube that demonstrates the process of making corner wall wooden shelves.
The Classic Workbench is constructed entirely with in-compression-for-eternity drawbored mortise and tenons. It's as solid as humans can make it, short of growing a tree in the shape of a bench. The bench arrives at your shop completely assembled and ready to use. It doesn't knock down. The bench is built to the highest standards of traditional German craftsmanship in the utopian village of Amana Iowa. Our collaboration with the craftsmen in Amana, along with our experience in traditional workholding has yielded a workbench that is truly heirloom quality, but offered at what we think is a very reasonable price. We consider our flagship Split-Top Roubo as nearing the pinnacle of bench design (if there is such a thing) but we wanted to offer an essential bench built to high standards--an approachable but bulletproof tool for passionate enthusiasts of all levels, but especially intended for those just getting into the craft. Our principal bench maker has been steeped in the craft at the Amana Furniture Shop for nearly 50 years. Needless to say, a century and a half of woodworking tradition in Amana directly back to 19th century Germany speaks for itself. Many of the Amana craftsmen are multi-generational woodworkers.

To mark the centerline, set a compass to span something more than half the width of the leg. Draw an arc from corner of the leg. The point where the arcs intersect will be on the centerline. With a centerline point on each end of the leg, place a scribe on the point, slide a straightedge up to touch the scribe. Do the same on the other end. When you have the straightedge positioned so that you can touch both points with the scribe, and in each case it is touching the straightedge - without moving the straightedge - scribe the line. Use scribes, rather than pencils or pens, because they make more precise marks.

My first attempt at making a cutting guide didn't work. What I ended up with worked fine for cutting panels, but the guide-strip was too narrow, and when the saw was extended fully for rough-cutting the 4x4's the clamp heads got in the way. So I made another. Actually, I made two more, so that I could cut one into shorter pieces that would be easier to handle.
A woodworker's workbench isn't a table, it's a work-holding system. It's not something you set things on top of, it's a tool that holds your work. Where a worktable might have a machinist's vise bolted to its top, a woodworker's bench is built to accommodate a number of different workholding mechanisms, such as bench dogs, planing stops, hold fasts, or board jacks, and will usually have one more woodworker's vises integrated into its structure.

My wife has given me the OK to buy a "Rancher"-style shed from Lowes and have it installed in the backyard. The discounted installed price will be about $2,600 and this includes the 12' x 8' structure along with a lot of upgrades (twin metal doors, a window, 2 skylights, storage, vents, etc.). I can save about $300 if I build it myself, but my skill level isn't there yet, so I'm going to pay Lowes to assemble it. (See Post #12 below for some photos of the shed and the space I have to work with.)