>>Index seek is better than Key Lookup. You may find articles by Craig Freedman really helpful.
>>
>>http://sqlblog.com/blogs/denis_gobo/archive/2008/05/23/6953.aspx
>>
>>Links to Craig's blog
>>
>>http://blogs.msdn.com/b/craigfr/
>>
>>I read the series of different kind of joins, but I think any article by him you read can teach a lot.
>
>Thanks, so basically, if the execution plan says Index seek at 4% and Key lookup at 92%, I would have to see what could be done to enhance the query.

Well, you can create covering index, so you will only see index seek. But covering indexes are expensive in terms of insers/updates.