Forum Moderators: open
And welcome to the boards TammieJ64 :)
There are variables, but sites that are up and running in time generally get crawled during the regularly monthly crawl, which is right around the first week of the month. Those sites can be expected to be included at the next update, which would be at the end of the month immediately after the crawl. Sites do need some Page Rank and at least one good link from a site/page already in the index, so that makes it important to make sure at least one such link is there in time. ODP is a very good one to get for starters.
Sites can make it in in between, but they often briefly appear and then disappear until the next regular update, so that's no cause for concern when it happens.
The great thing about google is without paying a penny, if your out there, you'll be in soon enough...
Its how high up thats the art ;)