The OWL at Purdue is a valuable and easy-to-use site for English students. http://owl.english.purdue.edu/owl/resource/594/2/ This link will take you to four pages on Prepositions with very helpful pictures which show you the meaning.
When you get to the bottom of the first page, click on ‘Next Resource’ to take you to the next page. You will see pictures which explain Prepositions of Direction, Movement, Spacial Relationships, Time and Place etc.
Check your knowledge of Prepositions of Direction – TO, ON, IN, with this exercise – http://owl.english.purdue.edu/exercises/2/14/35/ or you could try finding your own exercises on their site. Simply click on ‘OWL Exercises’ which is listed on the left side of the page.