If English isn't your first language, I'd highly recommend getting DVDS/Video Downloads. Bobo's work will be very difficult to understand if you don't know the terminology. Bobo's book was made into a four volume DVD set (
http://www.penguinmagic.com/p/1396), which may be far more worth your time and money.
Also, David Roth has some excellent DVDs. Though, if you're interested in his book, his book is not authored by him, it's by Richard Kaufman (I own it along with his DVDs. I highly recommend his works).
After you learn the basic moves and terminology, I'd highly recommend tracking down the 13 DVD volumes, "New York Coin Magic Seminar". Avoid wasting financial resources on one-trick videos. They're frequently a waste (emphasis on frequently as this doesn't always apply).
Anyways, some additional coin magicians that you may want to look up are:
Kainoa Harbottle
Homer Liwag
Dr. Sawa
Dan Watkins
Geoff Latta
Giacomo Bertini
Philippe Bougard & Clement Kerstenne
Dean Dill
Michael Rubinstein
David Stone
Johnny Wong
Michael Ammar
With regards to ring magic, the videos that I'm aware of are:
John Shryock "Ring in Walnut" (this is a video that is an exception to the rule that I stated above)
Worlds Greatest Magic "Finger Ring Magic"
Justin Miller "Ring Thru Finger"
De'Vo "De'ring"
David Jay "The Ring Master"