I agree that picking a race is a good way to get motivated? I sort of did it backwards, as I signed up for a 5K and then started running but was already working out pretty regularly (Tae Kwon Do 5-6 nights/ week...) and was able to run 5K right off the bat, which made the race fun, except I had been told 'you should be able to run 3 miles in 24 minutes for the black belt test' which made it more challenging! Regardless of your ability, a 'goal' like that can help make you train more and get ready.
I got Galloway's Book of Running as a gift recommended by my aunt, who does ultramarathons (50+ miles, 24 hour runs,etc.) and it is pretty informative, with a lot of tips about form, not so much you can't remember but suggestions about where to put your hands, how to control your steps and pace and also suggesting very strongly to do walk/running, whatever distance you are going for, as it reduces your risk of injury? I picked up Chi Running @ the running store today (no, they did not have the lime green Gel Kayanos :-() but put it back on the shelf as, w/ xmas coming, who knows what Santa might bring? It looked very interesting too.
I totally recommend finding good shoes by going to a running store that has treadmills. If you put different shoes on each foot and run on the treadmill, it has been my experience that the most comfortable shoes will become apparent much more than walking up and down the aisles at a non-specialty store. I've done a few laps around Sports Authority too, which is ok, but I think you'll get the best fit for both size and running style at a running store.
Re diabetes, I have been running (mostly, w/ some biking and a brief stint of Kung Fu...) for about 3 years now and as my 'main' workout for about 1.5 years. I had a pump when I started, which makes it a lot easier and the CGM will really help. I think that when I regaled my doctor w/ stories about 'well, I was gonna go 8 miles and my BG was 39 about 3 miles into it so I had some Smarties and sprinted 3 blocks and, about 15 min later, BG was back up to 85...' it may have helped get the CGM? I didn't have any resistance from her but I never know what goes on between her and Blue Cross? Even suggesting "I am going to start running" would make a doctor conclude you should get one. When I start, or when I switch from running to biking (or vice versa?) I will get more BG bang for my buck than when I've been at it a while? 3 miles will go for maybe 20-40 minutes, depending on how fast you are, if you stop to test your BG (not a bad idea...) and probably count as 'moderate' exercise for the charts in Think Like a Pancreas or Using Insulin about cutting boluses? I enjoy running a lot more if I have 'cleared the decks' by running when the insulin on board is gone from my system? After training for a while, if you can run 4 or 5 times/ week, you should be able to turn your basal down, it might go even faster or slower, so I would plan to test a lot? Sometimes your BG can also go up although lately, on the 6-10 mile runs, I've been trying to cut back on the carbs to no more than 10/ hit, in the hopes of cutting the spikes out. Sometimes it works and sometimes it doesn't. Unfortunately, I refuse to write anything down so I don't have precise data on that just yet? We'll see....