I think the best way to learn about startups and funding is to hear what founders have to say. For this I recommend Founders at Work: Stories of Startups' Early Days by Jessica Livingston, http://www.amazon.com/Founders-Work-Stories-Startups-Early/d... While this isn't specifically about funding, many of the founders talk about their funding experience, because this tends to be a painful part for many of them.

As mindcrime mentioned in his comment, Brad Feld's Venture Deals is a great book, though focused on raising from VCs.

Another great source is not books but YouTube. The "This week in venture capital" series is usually interesting. For example here is the most recent episode, with Naval Ravikant, co-founder of AngelList: http://www.youtube.com/watch?v=JP_MJCASwsY This way you don't only learn about startups and funding, but also about key players in the industry. I'm in the habit of watching those videos daily as I work out on my elliptical trainer... As I learn about a certain investor / founder in one video, I search for more videos of them. Some are more interesting than others. For example Mark Andreesen is always a pleasure to listen to.

If you prefer reading, some interesting relevant bloggers are Brad Feld, Fred Wilson, Chris Dixon and Mark Suster.