Micro SD cards

I use my sansa clip+ 4gb for audiobooks only, and when buying I bought a 4Gb micro card with it.

Do I load the books onto the card through my PC and the “Audible” manager programme, or insert the card into the player and download it through “Audible” manager, programme.

I am 80, and do not read very well, hence the need for talking books, I am new to all this and trust that you will extend a little “patience” in the event that I prove to be a little "thick?.

Maybe I should be asking  Audible these questions,?.

Ps my little grandson is helping me out.