Reward form a quest in Silithus: http://www.thottbot.com/?i=52083 (8)
You can also use your Onyxia trinket (+8 to all resses)
http://www.thottbot.com/?i=19211 form UBRS give +20 to all resistances.
Here's what I found in Maraudon that has nature resistance, Maraudon is very easy and can be solo'd by hunters or two-manned by other classes, I did it today with Xel and it was quite easy and we got good nature resistance.
Cloth:
http://www.thottbot.com/?i=38524 (12)
http://www.thottbot.com/?i=19972 (20)
Leather:
http://wow.allakhazam.com/db/item.html?witem=17728 (5)
http://wow.allakhazam.com/db/item.html?witem=17749 (10)
http://wow.allakhazam.com/db/item.html?witem=17751 (10)
Mail:
http://wow.allakhazam.com/db/item.html?witem=17767 (10)
Plate:
http://wow.allakhazam.com/db/item.html?witem=17711 (10)
http://wow.allakhazam.com/db/item.html?witem=17746 (15)
http://wow.allakhazam.com/db/item.html?witem=17734 (10)
Miscellanious:
http://wow.allakhazam.com/db/item.html?witem=17744 (10)
http://wow.allakhazam.com/db/item.html?witem=17745 (5)
http://www.thottbot.com/?i=38721 (10)
Hope this is of help to you, happy Nature resistance hunting
