I must warn you that speed reading isn't (in my opinion) the most important reading skill in the Verbal section. Being able to look up information and knowing where the right information is located is probably more important. Looking for keywords, picking up on structure, and tone are also important. This you may be able to do by skimming and using the 1st paragraph, topic sentence strategy.
Speed reading is fun though in other areas. When I started to speed read, it helped to use one of my hands sliding down the text at a rapid pace and letting my eyes race after it.