If you want to play them the first time around without any spoilers, I would recommend at least having a look at the sections dealing with creating your characters and party. It is far easier to create a bad party that doesn't work well for you than it is to create an effective party that works for you, thus prompting restart syndrom. The Dark Savant trilogy, much more so than a lot of the other older crpgs, placed a premium on effective character and party design and planning.
Beyond that, it is entirely possible to make it through all three without consulting walkthroughs. You might, however, want to look at the guides to get a sense of where you can do better next time, what you missed, etc.
