Right Start Math  by Joan Cotter
This program offers the best thought-out set of manipulatives and games I have ever seen.  The games are not merely practice of concepts, which would be very good in itself, but they actually teach concepts.  That is, they don't just reward the learning of concepts by letting you win if you did your homework; they actually engage you in the mastery of numbers, tables, etc, and this, not merely as rote, but as  pattern and number. Everyone I know who is using this program loves it and this includes a good friend with six children under 12 years.  The program is somewhat teacher intensive, for ten or fifteen minutes a day, but the children are happy. What a treat! 
This very engaging program program extends from the earliest years to fourth or fifth grade.

Math-U-See by Stephen Demme
A full curriculum in math, including manipulatives, video teacher's manual, text, and student exercises.
The first strength of this program is its clarity and its good manipulatives with exercise pages that review all previous lessons.
Its second strength is that each lesson (36 per book) has four pages of exercises so that if you get the point at once, you can go on at once without missing anything.  So it's not so boring.

Key Curriculum Good explanations, self-paced worktexts in every topic:  integers, decimals, fractions, geometry, algebra...

Books to read
Math for Those Who Hate Math -- enrichment after the basic curriculum.  You have time for this sort of thing if you use Math - U - See  And it is very important, because real mathematicians don't like plain ol' arithmetic much more than real children.  They want to do stuff with it.
Math for Smarty Pants  -- enrichment after the basic curriculum.  Same as above.
Patterns in Nature
The Curves of Life by Theodore Andrea Cook is a classic work showing how math describes various patterns and curves that are found in living creatures.
Innumeracy by John Allen Paulos  This is a reasoned lament for the state of math in the world today.  Innumeracy is like illiteracy -- it means being so uncomprehending of numbers that when the news reports

Math
Following is a list of books we have found particularly useful or beautiful over the years.  Keep in mind that math is not only about numbers, but about patterns which can often be most economically expressed with numbers.
MacBeth's list of math books is wonderful. In fact, all her book lists are exciting.