The top is supported by the top ends of the legs and the top sides of the top stretchers. Stand your legs on end on a flat surface (like my door) and see if they wobble. If you have an end that isn't quite stable, use it as a foot, where the leveler will make it's flaws unimportant. Check the top edge of each stretcher for straightness. If one has a bit of a bow, use it for a lower stretcher. It's less critical that the shelf be well supported along its length.
Building a bookcase or bookshelf is a fairly simple woodworking plan that you can get done in just a day or two. This is also a low-cost project as well and since the project idea is free, you don't have to worry about busting through your budget. Just follow the simple steps in the tutorial and enjoy your own company building a simple bookcase on this weekend.
This table top is also made from the hardest wood out of any manufacturer we reviewed: oak. In fairness, this can be both a blessing and a curse. The oak wood is extremely durable and noted for its lack of a porous nature. This means the top can withstand plenty of abuse from tool and workpieces. Moreover, you will not have to worry about liquids like lacquers and stains from being absorbed into the top. That said, the hard oak can also do a number on tool sharpness, dulling them prematurely if they are not carefully handled.