I uploaded my first images last week and although they have been approved, I can't find them in search, no matter what terms I use. If I search for the reference number, it appears, so it is obviously in the market, but if I search even for the exact title, it doesn't appear.
Go into your contributor control panel and be sure that you have set your keywords. Those keywords are what is used by the search. Be sure to choose keywords that are most relevant to your images in order of relevance.