Great question. Helping folks learn Braille is one of the things we're best at - you certainly came to the right place.
The absolute most popular product we carry for this purpose is the "Braille for the Sighted" package. This print booklet will teach you the basics of Braille, how the letters and numbers are made, and so on. Best of all, it comes with a Braille companion book, so you can practice doing the exercises and puzzles in actual Braille whenever you like. Well worth the $19.95 price tag.
An excellent product to reinforce what you're learning is the Braille Flash Cards. Costing only $13.95, this invaluable set of over 100 cards has each Braille letter, number, or punctuation mark on a separate card, featuring both raised print and embossed Braille. There are even a few words and phraises to practice with.
Finally, the Braille Alphabet Tray is an excellent quick-reference to always have with you to insure you don't forget a particular letter or number. This hard-plastic tray has raised Braille and large debossed print lettering, and is only $9.95.
These and many more learning Braille products can be found on our website. Just click on the Braille Workshop, then ABC's of Braille.
Hope this helps. All the best on the Braille Trail!