I don't think it matters too much morning or night, although if you make it the morning there's less chance of upsets overnight if something doesn't agree with your LO.
We started at night with DD2 but I'm pretty sure we started one or two of the others in the morning.

20-30 min after a milk feed should be enough for them to be interested, although again I don't think it matters hugely - a long as it's not too close before a BF, milk is still the most important thing KWIM?

We started at one meal a day and one month on we are having two most days (breakfast & dinner).