Creating a workshop is a daunting prospect.  In fact, I'm fairly daunted right now.  Fortunately, the Instructables community has provided a huge resource of workshop-related projects. 

This guide collects a cross-section of Instructables, from building a workbench, to organizing your tools, to decorating with a Tyrannosaurus Wrench (which still cracks me up).  Some are cheap and super-simple (like mine) and some require more time, tools and talent.  Hope these help you plan what you need and maybe go DIY on some aspects that may not have occurred to you.