The state of Pennsylvania is a regulated homeschooling state. (one of the seven strictest in the U.S.) This means before every school year the home education instructor (parent or guardian who is the primary teacher) must provide a notarized affidavit each year with the local superintendents office. Age and grade appropriate objectives and a formal letter are to be provided as well at this time. At the end of the year the law requires you to submit to your local district a portfolio that includes an evaluation of the portfolio by a state approved evaluator. Some states have very little involvement with homeschoolers. Those who live in a regulated state often have the benefit of free curriculum material. 

If you live in one of the states that regulate and define "appropriate education" legislation states that you must be provided with learning material if you request it from your local public school. To find out if you qualify you will have to do the leg work yourself. I have not found any wonderful "look here" links. I've gone by researching and word of mouth. Great resources for finding the law would be The HSLDA or The Department of Education. If you are not on a budget  and or have devised a curriculum of your own congratulations your in luck! If you live in Pennsylvania contact your local school district and formally request to borrow learning materials, if they deny you the right to borrow material the Pennsylvania Department of Education website directly quotes the following-

Legislation 24 P.S. § 13-1327.1 Home education program
(f-) The school district of residence shall, at the request of the supervisor, lend to the home education program copies of the school district's planned courses, textbooks and other curriculum materials appropriate to the student's age and grade level.

Our local school district claims to have no text books for subjects other than English and Math. So I use the English and Math provided and supplement with a great deal of additional resources such as work books and library books. Following is what we are doing for Riley's Second grade school year. I have come up with a combination of materials. We are not religiously affiliated or following any specific program. Our "curriculum" is a hodge podge of this and that, our reading list grows as we go. These are some of the products we are using this year.

Second Grade Curriculum
Scott Foresman- Reading
enVision- Math

Smart Alec- Reading Comprehension Grade 2 (purchased at Five Below)
Smart Alec- Math word Problems Grade 2 (purchased at Five Below)

(1st Grade) Completed Reading List & Portfolio