For those interested, here is something I wrote up for members who asked on another board.
Yuca (Cassava) looks like this at the supermarket.
If you're like me, you go ahead and break a piece open to look at the inside. You want it to be white on the inside, not tan or brown. Tan or brown will mean it's gone bad and will even have a slight funk to it. That is why I break a chunk off because that is the only sure way to tell.
White like this.
Tan/brown = BAD
First you peel the rough brown skin.
Then you cut into wedges, chunks, or even like fries.
Add a teaspoon of salt to the pot and boil for about 10-15 minutes until they're soft.
Then you remove the inner core strand.
Pat dry then fry away until golden brown!
This picture shows the whole process.