I'm just reading the series for the first time, and the time jumps in the first book really threw me off too. However you should be aware that it mostly stops after the first book. The second book (Foundation and Empire) has two stories, but most of it focuses on the second one (The Mule), and the books after that are more like regular novels with no jumps.

For me the first book was by far the worst and I consider it more of a background filler than an actual story. I enjoyed the rest of the series far more, especially Foundation's Edge.