There is an article about this language point on this website that you might find interesting - BBC World Service | Learning English | Learn it
The problem for learners with the use of these words is that some expressions sound more natural with small, and others sound more natural with little. It's a question of collocation.
For more work on collocations, there are some good books for students including -
Check Your Vocabulary for Natural English Collocations - All You Need to Improve Your Vocabulary (Check Your Vocabulary) by: Jon Marks - Alison Wooder