Sludge Fens are directly north of far watch post. There is a shredder in the fens that gives a mission you should consider Mabinogi Gold taking if you have a group.
The Sam flange can be located by going due-west of the sludge fens. After you activate the console, one valve is on the main pipe, one is on the rusty pipe going up, and the third is by the tracks. The named NPC sniggles is in the hut next to the Sam flange.
A kodo spawns in the southern oasis and a little south of the sludge fens; you’ll need to know this for a collection quest.
Prowlers can be found under trees off the east portion of the north road. Harpies are the best things to farm in the northwest for levels 16-19. The Wailing caverns are to the south-west of crossroads.
When you hit level 15 and get the Seplecur cape quest, you should head over to Silver pine and do the easy missions.
Silver pine will actually give you a cape quest to the barrens, so it all works out. Do Silver pine until you reach level 17? A good NPC to farm are the wizards of Amber mill, especially for Rogues with kick.