With Microsoft ditching the venerable Start Menu with Windows 8, plenty of vendors are stepping in to fill the void. StartMenuPlus8 doesn't exactly replicate the Windows Start Menu, but functionally it's the equivalent. Visit Windows 8 Advisor.
StartMenuPlus8 sits on the desktop taskbar; however, it's not where you'd normally expect it on the far left, but to the right as a program icon. Once you're used to that, simply click it and you get the Start Menu functionality that you want. You can access your programs, folders, the control panel, etc. all in the fashion you're used to. The program is also highly configurable, and has some features such as configurable task lists that might interest you.
I find the effort behind StartMenuPlus8 worthy, but it's not as handsome or as slick as Stardock's Start8, which melds almost seamlessly with the operating system and replicates the Start Menu and W8 UI behavior to a tee (all while costing the same $5). Still, you might want to take a look if you want a Start Menu replacement with more options.