R - I agree with Sara, 8 months is old for 3 naps. However, you have to be able to make it through the day as well. Maybe you could post your day so we can help a little more.
Kate - You're in the right place. I would say your DS is ready to drop the CN. When extending the A times, it is best to start with one. We started with the morning one (still working on it some days) and then moved to the second A time, and so on. As far as how long A time after the CN, I'm not the best one maybe the others can help. But I'd say try capping the nap to 15 min just to get a reasonable BT. So if DS napped from 4-4:15, you could try a 6pm BT. If he was seeming really tired after that nap then you could even do a little earlier and hope he just tacks on. We ended up just cutting the CN all together and doing EBT. Right now your days are about 13 hrs which is okay, but maybe a little long as you adjust your A times. To answer your last question, I wouldn't cap your other naps unless they get too long - 1-1.5 hours is good, giving you around 3 hrs day sleep.
HTH.
I'm just struggling with S! I'm not sure if it is her teething or if it is our routine. I thought we had the days looking good, but the nights are getting worse. Yesterday was something like:
WU/E - 8 (Let her sleep a touch after a 6 am nursing since it was a rough night)
E - 9 Breakfast
S - 10:35-12:45
E - 1pm BF
E - 2:15 Lunch
S - 3:15-4 (Def. UT I'm sure)
E - 5 Dinner
E - 6:30 BF
BT - 6:45 (But then she woke numerous times from 8-midnight, when I finally gave in and nursed her and gave her Advil)
I know that she was UT at her second nap, and then probably OT at BT, and we missed a nursing due to her short nap and not sure how to get it all in by BT. I also think we are teething a bit, though I don't think teeth will pop any time soon, but we have runny nose and chomping on things like crazy. I'm just loosing it. We were working on not feeding at night. Well, I'd done one day successfully. I don't think hunger is generally the issue. I just need sleep!