do u know any free book download site????

Try your local library - they often have a subscription to NetLibrary and then you can access a huge collection to download for free. Check their website or call. If your local library doesn't offer it, try looking at one of the large systems (like cuyahogalibrary.org) and see about becoming a non-resident patron. Often there is a small fee to join as a non-resident, but from then on you will have free access to the audiobooks and ebooks that they offer. This way you can get some great bestsellers and popular items, and not just the random items you find around the internet.