The English File by Oxford University Press is excellent. It builds up grammar, vocabulary and useful phrases gradually, incorporating pronunciation practice. There is a teacher's book to accompany it that includes photocopiable resources.
Headway Beginner (also by OUP) is another good choice. It also works on the 4 skills but is a little more demanding on the students. You'll know best which suits your students.
English in Use by Cambridge University Press is also very good. There's a workbook to accompany it which gives extra vocabulary and listening practice.
I hope you enjoy teaching the beginners whichever book you use.