I was wondering if there are any particular dangers to look out for when downloading books to read, particularly using an Android Tablet. Are there any recommended safe sites please?
Free, http://www.gutenberg.org/wiki/Main_Page Paid, Amazon for example. I don't know of any particular attack via infected eBooks. Have your device always configured to only accept installations from the official app store and never click 'accept' on any prompt to install or download something that you didn't asked for. If you try to download an eBook and something tries to install, go back or cancel.
.chm is listed as a potentially dangerous file type at some sites, for example at http://www.ttu.edu/safecomputing/lubbock/recommended/fileextensions.php.