I really don't know anything about preschool or kindergarten materials.  :D

What I do know is that over the course of the past 16 years, we've used a lot, seen a lot, ditched a lot, and loved a lot.  Because this is a subject that could garner a ridiculously long post for me, I thought I'd offer here only the things that have really worked for us.  If you don't see something mentioned, it's likely because we either haven't used it, or we have used it without success.

In the earliest years, I like to offer learning tools that are hands-on.  Preschool attention spans are notoriously short, so if I can get ten or fifteen minutes out of one of these items, I am happy.

Lauri Alphabet Puzzles are my favorite way to purposefully review the alphabet with a preschooler.  The puzzle's bumpy texture and bright colors allow the child to feel the letter, trace the letter with a finger or two, and associate colors as well.

Lauri also makes lower case alphabet puzzles, number play puzzles, and many others: cars, flowers, people, and play packs such as this one.  The price is right, they're pretty durable (ours have lasted over ten years), and the company will replace missing pieces.  Incidentally, I love to put these away as birthday and Christmas gifts; they don't know I'm sneaking "school" in that way.

Wedgits are building blocks that are suited for little hands because they are larger and easier to hold.  The pieces drop right into each other and stack in interesting geometric ways (aha!  math!).  Bonus: they can be thrown in the dishwasher.  Another bonus: older kids like them, too.

Wikki Stix allow preschoolers to bend the little waxy sticks into any shape, including letters (my older kids have been known to write messages to dad on the front door).  Wikki Stix are quiet, mess-free, and intriguing.  Perfect for the car or church, too!

Big, fat crayons.  I'm sure you're familiar.

Preschool in Grammy and Pop Pop's motorhome

♥ Kumon workbooks are a lovely little thing for preschoolers.  Books range in subject from math to rhyming, cutting to tracing.  Workbooks can get a bad rap in some homeschooling circles, but to my way of thinking, they are a nifty way to keep a preschooler happy, productive, and learning.

Our preschooler loves games, too.  And pretty much anything with Charlie and Lola (including pink milk)

Kindergarten is simple here.  I haven't changed my approach too much with each child, except with the last two I have waited to teach reading.  While I was busy helping the older kids, our fifth child decided she didn't need me to teach her and she taught herself to read.  She's an amazing reader, so I'm not expecting the same from the others younger than she.  It was quite a bonus though!

♥ We use TATRAS in our home.  TATRAS stands for "Teach America to Read and Spell".  I love this approach, adore the man who authored the book, see huge and wonderful results, but I do wish it was laid out a little better.  Don't let the book scare you off; it's a bit busy (ie, too many things going on each page), but it works and it works well.  TATRAS employs the vertical phonics method, which you can read about here.

The reason I adore the author is that when I first began using TATRAS nine years ago, I was flabergasted to receive a phone call from him after I had purchased the program.  He wanted to make sure I understood it and knew I could call him at any time if I had any questions.  Six weeks later, he called me again to follow up.  Now that's a man who stands behind his product and believes in what he is doing.

♥ We jump right into Rod and Staff preschool, which is equivalent to kindergarten.  Motor skills, letters, numbers, comprehension, and following directions are all covered in the series.  These books are long on preparation and short on fluff. The illustrations are engaging and the work leads to really solid skills needed for first grade. They are also very reasonably priced.

Don't forget to go see Cheryl's Marvelous Monday post.  We've only one left; these have been fun, haven't they?