I'm very sorry for your son's diagnosis. I know that it is overwhelming right now, but hang in there...it does get easier!
In the beginning, I personally recommend keeping a paper-and-pen log and/or journal. It will be easier for you to "see" the data you need so you can easily see where his BG is too high or too low, and see what adjustments are working for him. Also, a food log with carb counts is very helpful in the beginning. If he tends to eat a lot of the same foods, you can just flip back a day or two to the last time he had that food and see what the carb count (per serving) was.
The log sheet I use for our son, William (12, dx 5/13/09) is a hybrid of two different logs our Ped Endo uses. Because he does not go to school and we don't really keep to a "schedule" as a family, meals can be somewhat erratic. So, my log sheet has a column for each "awake" hour to track data on an hour-by-hour basis. If your son's meal are more regular, you can just use a column for each meal. The information I track for each entry includes: time of BG test, BG, #carbs, bolus (how much insulin for the meal), and correction (if his BG was out of range, how much additional insulin was given). I also tend to use highlighters for "out of range" BG's so I can more easily see where adjustments may need to be made (orange for high, blue for low). If I'm considering changing a carb/insulin ratio for a particular segment of the day, I'll make note above each entry what carb/insluin ratio I used. I also scribble notes to indicate if he's eaten a "difficult" food (one that makes him high), if there's been unusual activity (we've been camping and traveling a lot), extended exercise, etc. which might effect his BG. If you would like to contact me privately I can send you files with a couple of different logs I've used...maybe one of them will work for you. Hueyhome@msn.com
I tried out a few diabetes management apps this past spring, but was not completely satisfied with any of them. It's probably a little early for you to be looking at apps...you'll want to get a better feel for what data is most important for you to track, how you like to see/review the data, how your endo wants the logs reported, etc. Once you get to that point, you'll have a better idea what apps may work well for you. I personally want one that not only captures BG, doses, activity, and has a food library, but also captures carb/insulin ratios used and correction factors used. And it has to export and be printable in a format that makes sense for us.
Okay, that was a lot. Sorry. Please don't hesitate to contact me privately if you'd like to chat, or want to see some sample logs.
Hang in there!