HI,
I would move them to a pot when the leaves are about the size of a dime. I use a light mix of 1-1-1 and wick all my plants. The small plantlets I start out in 3oz Solo cups and repot into larger as needed. My minis and semis always stay in the cups.
Fred in NJ

I agree with Fred, allow the plantlets to get bigger and develop a stronger root system before moving them. Also, to answer your question about how long to flowering from propagation, I think it depends on the conditions. I just recently rooted a sucker, maybe 5 or 6 weeks ago, and it is blooming, but that is common. From a leaf to blooms? I've had them bloom at a few months. And I have seen photos of little baby plants blooming while still attached to their mama leaf. You just never know@!

Does this website move reeeaaaallllyy slow these days or is it me??

I started a bunch of AV from a leaf in solo cups last November '08 and they all started to grow little leaves. They are still living in the solo cups with very tiny leaves and now growing long "air roots" like coming out from their sides. Now what? They are not root bound at all. Please help me on to the next step. donna

I think I'm hearing you say that you planted leaves and the leaves did what they are supposed to, they produced new plants. All those leaves you see are several new plants.

These need to be carefully divided, removed from the "mother" leaf, and planted on their own.

Try the following links:
Propagation basics
Rob's Instructions
AVSA Instructions

I haven't yet divided mine, as my plantlets are too small, but I had saved these links so I have some idea of what to do when the time comes.