I'm another new boy on the block with, I'm told, my RasPi on the way.
I've just bought an SD4 Kingston 8GB card in readiness and had some issues trying to access it through two different card readers.Other older cards I have worked OK though they were much lower capacity.I then tried the Kingston in my laptop card slot and it worked OK as it did on my Kodak printer card reader slot. I could access & write to it as it should.
On comparing the contact side of the new Kingston & other two older working cards I noticed a different "pinning" style which may be the reason of non compatability with the admittedly older card readers. I wonder if anyone else has made this observation and would value a reply on the matter. I do hope the SD socket on the RasPi is up to date for the later card contact arrangement!!