Most of the days will take care of themselves in that it will be like starting over again for all of you since the presence of the others will through even the current routines you are establishing out the window not to mention nap times will all be different by Fall. Personally I would start to have them coming on the same days but half days. That will give you the best chance to work out a routine and a short time for the kids and then home for lunch and nap and then eventually work up to lunch first and then home. You need to see what they are like when they are all togehter. Also the one on one time you are giving them now may come back to haunt you and backfire in the sense of instead of getting them used to your daycare you have gotten them used to your undivided attention which is exactly what doesn't happen in group care.

Develop a basic plan that takes into account what you need to do in the day. Use large blocks of time and fill them in with things like diaper changes which can take half an hour if you are doing several, naptime, snack - again long if you are doing the feeding. As long as you have an idea of what you need to do next the timing isn't as important. Just watch for signs it is time to move on to the next phase such as rubbing eyes whether the schedule says naptime is then or an hour away. But really reconsider the one on one visits for too many weeks.