That's fine for learning about the ancient history of guitar, but most people with a general interest really only want to know about the electric guitar; when was it invented, and when it was popularized, who popularized it, etc. The Lemelson Center site provides an excellent analysis, in a feature entitled "From Frying Pan to Flying V: The Rise of the Electric Guitar". And, there are other good informational sites on the WWW about the electric guitar too; JimiJunior's History of the Electric Guitar analyzes the rise in popularity of the electric guitar through it's use by notable jazz guitarists.
And, what about the individual guitar companies? Some of them (Fender for example) haven't gone through the trouble of providing a detailed online history of their guitars, which is a shame. Others, though, like Gibson, have provided on their site a more in depth study of the place in history their guitars had. In a four part document entitled Gibson History: The Early Years, the folks at Gibson provide us with a glimpse on how important their company was to the development of the electric guitar.
One of the first musical genres that the guitar really became integral to was the blues. It's very hard to picture the blues developing without the presence of the guitar. Bluesman Harry has put together an excellent Blues History site that includes explanations of the role of the guitar in the music, and the effect that the creation of the electric guitar had on the blues.
Knowing and appreciating the history of the guitar may not be essential to being a great guitarist. For some, it may not even be of interest. But, I've always believed that understanding and being familiar with the history of music, and it's musicians, gives one a broader perspective, and a more comprehensive philosophy on what it means to be a musician. I hope you'll find something on these sites that will spark a similar sentiment.

