http://www.istqb.org/downloads/viewcategory/16.html
Reference Book: FOUNDATIONS OF SOFTWARE TESTING ISTQB CERTIFICATION Dorothy Graham
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCsQFjAA&url=http%3A%2F%2Fapi.ning.com%2Ffiles%2F3loaqsYd*X79APGpzKjrwfsYnULTkvQVVy1NG4uHYXDVvODL7V7BO90iU4gcu-8x-AHaSXc2gZd3Hvn3Pu5**1H8XXmxIIIZ%2FRexBlack_istqb_Material.pdf&ei=WGMvUsqOHeL9iAf0rYHIAw&usg=AFQjCNH3_iTce2eXvY9pqueoDc5ziJuAxA&sig2=mM3Mxr0aJpSdImmuQMwelA&bvm=bv.51773540,d.aGc
Sample questions and study material:
http://www.softwaretestinggenius.com/full-study-material-for-istqb-foundation-to-all-3-advanced-level-certification-exams
Tips: Foundation level exam is typically based on the syllabus. Please try to cover the syllabus completely. Do solve questions on test design techniques, test coverage etc.
Do post your query for any clarification on the same or if you want explanation on any topic related to istqb syllabus.
All the very best for your exam.