not idiotic questions at all! like with most things, i stressed this one and then ended up finding out that it was all good.
your darn ticker isn't showing itself yet so i am trying desperately to remember how old your lo is
as i could imagine that that would make certain things different.
for your first question- i was going back to my same old job so that was out of my hands... but the nursery did want as much time as possible to plan Ethan's entry into nursery. tho, i DID base the days i would work on Ethan's nursery availability (but then again i work 3 long days which is equivilent to 4 days so figuring out how hours will work part time is different to full time jobs)
the aclimatisation process worked like this: i left him for a half hour and filled in forms whilst he hung out in his "class" (of babies), the next visit i left him for an hour and the next time a couple of hours. all visits were fine and they would have called my mobile had they needed me to calm him etc but as i had already had a long chat with his key worker (who was there for all of his visits) and had written volumes about him, it went fine.
also, when he moves up into the next "class" he visits them from his own class but i am not involved in this process, i eventually meet the new key worker
i used to drop into bf on my lunch as Ethan started nursery at 8 months and that really helped me feel confident about my choice and i loved seeing him and touching base (gosh it was hard to stop).
hope all this helps! things are quite different of course with different settings and scenarios. hope its as successful for you as it was for us.