Summer SAT Prep

<p>With summer and then my Junior year approaching I am planning to really start to prep for the SAT. Over this summer I am going to begin and I am wondering if anyone knows which books are best for practice? Ive heard about the big blue book but any other recommendations? Also does anyone know from experience if self-prep is sufficient and will I be able to see a significant increase in my score if I put in the work? or do I need to sign up and pay for a prep place like Huntington? Thank you </p>