Making an Ebook?

I'm putting together an E-Book, my subject might be hit or miss I'm not really sure at the moment, but I figure trying is better than not. If anyone has experience with E-Books it'd be great if they could give me advice.

Also what software should I use to create the E-Book? What are somethings I should do in order to make the E-Book look professional? Lastly can I get a link to some good looking E-Books?

I'm good with graphic design and what not and thinking I might make it into a series so I want to produce a quality good looking book and not like some of the really terrible books I see people have made. Sure those get the information across but they just look very unprofessional, which makes you question your confidence in their advice.