If you're level 35, the best place to solo grind on mobs is Arathi Highlands, the Witherbark Headhunters. They're plentiful, well concentrated, and not too many other players hang out here. They drop silver. You can kill them quickly without too much downtime.
The way I look up the best thing to kill is using
Thottbot's NPC search. If you're 35, search for level 34's, aggressive to alliance/horde. Sort by Kills. This will show you what most people kill, and people kill that stuff because it makes coin.
This method is how I got to 60, and when I was done, I had so much coin I was the first person in my guild to buy an epic mount. (This was before the Dreadsteed quest was in the game so yeah... 900g).
Solo grinding might be a little dull, but frankly it's peaceful, easy, no running around all over the world, make fast xp, and make fast coin. I always did the quests that rewarded something I would actually use, or if I was playing with a guildy, questing is better.
Anyway, I realize lots of people find this method too boring to stand, so questing you shall go. Others in this thread already pointed out Arathi Highlands so you'll be okay.
You're big enough to start spending time in Scarlet Monastery. Can't get ganked in the instance.