You can buy tabletop herb gardens complete with a grow light, but their cost (often $100 or more) can be excessive. For example, here's a link to a very nice Tabletop Herb Garden Kit, but it costs over $100. Our goal was to avoid buying expensive fresh herbs from the produce isle, so why would we want to spend $100+ to do that? Our little Herb Garden cost us about $25, but would be even less expensive if you already owned a suitable florescent light that you could re-purpose for the project.
We needed to supplement the amount of natural light provided by our north facing kitchen window. To do this we purchased an inexpensive 18" fluorescent light fixture (fitted with an 18" grow light) and attached it to the bottom of the window blinds. By attaching the light to the blinds we could easily raise and lower the light, as well as set the light at an angle if necessary to maximize the amount of light reaching the herbs.
When choosing your window, be sure to pick a window that is neither too hot or two cold for your herbs. For example, a south facing window in Arizona might get too much light and heat for your herbs scorching them in the hot sun, while a poorly insulated (i.e. single pane) window in North Dakota during a chilly winter might expose your herbs to air that is too cold to allow your herbs to sprout. In other words, your kitchen window may or may not be the best window for this project. You'll want a nice cosy warm (but not hot) environment for your herbs to sprout.