I consider myself poor in plane euclidean geometry. so I need a good geometry book which contains very good theory, and a collection a large number of solved problems, and the end of each part.This book also should start from the basic school level theorems till the olympiad level.
If you want to go straight into Geometry, try "Introduction to Geometry" by Richard Rusczyk
If you want to brush up on other math too, try "The Art of Problem Solving I/II" by Sandor Lehoczky and Richard Rusczyk, which has a good amount of geometry.
If you want a book with more theory, try "Geometry for College Students (Pure and Applied Undergraduate Texts)" by I. Martin Isaacs.
Your goto site for competition math should be The Art of Problem Solving. Just get an account on the forums and go to the geometry section and do problems without looking at the answers first, it's a great resource!