There is no doubt that one of the most important woodworking tools when you're using hand tools is a workbench. Having the ability to secure a piece of wood to something solid is essential. For the most part you have two choices: you can buy a pre-made bench or you can make your own. I usually recommend that woodworkers make their own bench because you can make it the size that is specific to you.
My bench is about 60" long and around 20" wide. Anything bigger than that and I have trouble getting around it to work. Another plus to making your own is the control over the height. I'm 6'2" so the bench height that works for me is not the same as the height required for someone who is 5'5" or 6'8". For most work I think the bench should be around the distance from the floor to your wrist joint. This is just a general rule - ideally you want to be comfortable at your bench so you should make it the height that works for you.
Making your own bench can seem a bit daunting but it's not as hard as you would think. A logical question that gets asked is "How do you make bench when you don't have a bench"?
Enter the ubiquitous portable work bench. This style of workbench has been around for many years. My dad had one and he used it for a lot of projects around the house. You can find these benches new at many home centres, made by many companies for a reasonable price. You can also find them at yard sales and flea markets for $5 - 10.
These make excellent starter benches. The only advice I would give is to remove the thin, often cheap top and replace it with something a bit more robust. I added hunks of 2 x 8 to mine which gives me 1-1/2" of thickness and adds a bit more weight to it. This extra thickness also allows me to use various bench accessories like holdfasts or planing stops to help secure the work.
You don't need an 8-foot long aircraft carrier for a bench to get started. Kitchen tables have been know to become good work benches but it's hard to beat a $5 yard sale find. The best part is that you will always find a use for this small bench even when you do eventually make a your own proper workbench.
I'll be soon building a new bench to replace the first one I made after graduating from Rosewood Studio. It was (and is) a good bench but it just doesn't suit the way I work any more. The old bench is being donated to a co-worker who is just getting into hand-tool woodworking. Hopefully he gets as much use as I did out of it.
In order to understand, you must do. - V