I agree with S.E.H. that it would be helpful to know more about your students needs, but there are a few suggestions I can make anyway.
First, before you even think about resources, you will need to determine your goals and objectives for this student. If you have never set goals for students with special needs, it may be helpful to consult your special education/resource teacher--they will probably have an understanding of that student's needs and they should be able to help you even if they are not musical. They should also be able to tell you if any accommodations have been put in place for that student.
If you have a paraprofessional in your room, then that person should be able to provide one-on-one support for your special needs student. Just make sure you go over your plan with the paraprofessional so they understand what your expectations are.
Once you have determined your student's individual goals, you can then decide which resources will help the student best achieve the outcomes. You may, depending on the student's needs, have to create your own resources for that student or, If you are teaching in ensemble format, write out simplified parts. I don't know of any guitar specific resources, but I can recommend, "Teaching Music to Special Needs: A Label Free Approach" by Hammel and Hourigan as general resource.