First, if you're looking at doing your Sport Pilot Training on an all-day, every-day basis until it's complete, it could be incredibly intense. Most of my instrument students say they were surprised by the level of intensity of such a program -- 8-9 hours a day, 10 days in a row, plus an hour or more of homework every night. If you do this on vacation, make sure you're off work for 2-4 days more than the course will take, because you'll probably need the extra days at the end to recover before going back to work or school.
Second, that which is quickly learned is as quickly forgotten unless as quickly exercised. In order to "fix" the newly/quickly learned material in your brain, you must fly a couple of times a week for four to six weeks starting immediately after the practical test. If you don't, within a month, you'll be as though you never took the course (well, not quite that bad, but you certainly won't be ready to launch solo on a real cross-country flight with a passenger somewhere you've never been before.
Third, you must be academically prepared. If your only ground training before the intensive completion course is one of those 2-day written test cram courses, you won't know anything but the answers to the written test, and you will not be able to finish the flight course as quickly as you might expect-- figure two to four days extra to learn all the material that would otherwise be learned in a real ground training course. I recommend any or all of the following, choice based on your own learning style (and whether or not you can sit still for Martha King):
• Formal ground school of 40 hours or so classroom plus home assignments (like those offered by many flight schools and community colleges)
• Self-paced computer based training course like Jeppesen's FliteSchool
• DVD course like King or others
• Book learning, using a good Sport Pilot training manual , not just a written or practical test guide.
In addition, you should study the following books:
• Current FAR/AIM (especially the ASA version with the list of recommended FAR's and AIM sections for Sport Pilot
• FAA AC 00-6A Aviation Weather
• FAA AC 00-45F Aviation Weather Products
Finally, you must dedicate yourself entirely to the program. Don't just turn off your Blackberry -- leave it in the office. Explain to your family that this isn't a vacation, this isn't even work -- they can't expect you to participate in anything other than your training for the duration. Forget about catching up on your reading (other than your training books) or email or internet chat. You will eat, sleep, and breathe flying for the duration of the course, and if you clutter your mind with, or spend your time on, anything else, it won't happen on schedule.
With this preparation, you will find an intensive completion program productive and useful. Without this preparation, you'll just end up tired and frustrated – and your instructor will, too, because s/he wants you to succeed just as much as you do.