Take a look at the thousands of photos has of pendants over islands and see whether you like big pendants or small ones, elongated ones or round ones, colored ones or metallic...there are so many choices that you need to pinpoint what you like. Then consider how many of them your island will need. You don't want anyone bonking their head at the end of the island by leaning forward into a pendant, so you must allow 12 to 18" of space at each end of the island where there will NOT be a pendant. Then you will allow space between the pendants. A lighting store may be able to advise you also.