I'm interested in buying piano books to concentrate on improving certain areas. The books must be suitable for Beginner to Late Beginner level. I'd like to know your book recommendations for the each of the topics below:

1. Sight Reading
2. Rhythm training
3. Classical Repertoire (I'm interested in the "Succeeding With the Masters" series or is the "Celebration" series better?)

It would be nice if the books are beginner-friendly enough that I can work on them even without constant supervision from my teacher. (Because we don't get to meet enough!)

Any suggestions? Any other books on different topics that you could recommend? I'm open to anything as long as it could help a beginner like me

I do not recommend the Celebration Series since you'll be doing it on your own. There's a proper order to learning pieces, and I think you'd be better off with a different book. One such book is Francis Clark's Keyboard for the Adult Beginner. It's not the flashiest book out there, and it doesn't come with CDs. However, every chapter contains sight reading examples and rhythms examples, as well as technical exercises and repertoire. It begins with the assumption that you know the basics, but the preface for the student outlines them just in case you don't know something.

It sound like this would be a great starting point for you.

Ask your instructor, for recommendations, that way you and your instructor could have some very interesting and productive sessions.

I would suggest Succeeding with the Masters is a bit advanced if you are just beginning. The allied Festival Collection begins with simpler pieces, a wider range of composers, including 20th century, but no teaching notes. I'd agree with asking your teacher for recommendations.

Keith Snell's series is good for classical music. It ranges from Preperatory through Level 10 and each level has pieces that are chosen to be very close in level.

You can see a lot of details of the series at www.kjos.com .

Thanks
Rich