To start baby solids, I think the biggest question may be, what should the baby eat, and when?
I made the following chart (roughly) according to the two books that I have (the numbers indicate months old of the baby):
(Note: In SBF, "4+" is actually labeled as "beginner eaters.")
If you only want to get one book, I would suggest SBF. It contains probably all the information you want to know... perhaps too much so it's a bit overwhelming. (The book is more than an inch thick!) The WBFG has a website, so you don't really need to buy the book. But I like to compare information, use more than one source. The WBFG seems to have better recipes.
Unfortunately, both books will not tell you EXACTLY what to do. (Which was something I was looking for...) Every baby is different, so you have to decide how many meals and how much you are going to feed your baby. Generally start with one in the morning (8-9am), then add another one in the afternoon (4-5pm), lastly add one around noon (12-1pm).
I don't think you need to be too rigid to follow the chart as when to introduce what. Probably within a month should be okay. But do start with ones that are for 4 months or older (4+); and don't feed raw fruit to baby before 8 months.