Dr. Seuss has written and illustrated several world-famous books.  Here they are in the order of their publication.  I think I may be missing a couple though.
 

And To Think That I Saw It On Mulberry Street
The 500 Hats of Bartholomew Cubbins
The King's Stilts
Horton Hatches The Egg
McElligot's Pool
Thidwick, The Big-Hearted Moose
Bartholomew and the Oobleck
If I Ran The Zoo
Scrambled Eggs Super!
Horton Hears A Who
On Beyond Zebra
If I Ran The Circus
How The Grinch Stole Christmas
Yertle the Turtle and Other Stories
Happy Birthday to You!
The Sneetches and Other Stories
Dr. Seuss's Sleep Book
I Had Trouble in Getting to Solla Sollew
The Cat in the Hat Songbook
I Can Lick 30 Tigers Today
I Can Draw Myself
The Lorax
Did I Ever Tell You How Lucky You Are?
Hunches in Bunches
The Butter Battle Book
You're Only Old Once!
Oh, The Places You'll Go!
Daisy-Head Mayzie

BEGINNER BOOKS

The Cat in the Hat
The Cat in the Hat Comes Back
One Fish, Two Fish, Red Fish, Blue Fish
Green Eggs and Ham
Hop on Pop
Dr. Seuss's ABC
Fox in Socks
The Foot Book
Mr. Brown Can Moo! Can You?
Marvin K. Mooney, Will You Please Go Now!
Shape of Me and Other Stuff
There's a Wocket In My Pocket
Oh, The Thinks You Can Think!
The Cat's Quizzer
I Can Read With My Eyes Shut