I need to start reading The TCP/IP Guide.

I have to admit that compared to other informative guides/tutorials/articles out there, this guide isn't so cluttered. However, I still find it a little bit hard to read, especially when reading for several hours.

I don't know if it's the font, the contrast or the spacing, but this is why I've always preferred learning from books rather than from the internet.

What can I do to make this guide more readable? I am reading it on Google Chrome.