"How much" depends a bit. For a caster, priority one is getting enough money for spells. Weapons and armor is second priority, if not tenth priority compared to spells.
A great and safe place to farm some newbie money is East and West Commonlands. I would go there at around level 10 or so. Run around and focus on killing the following mobs:
Orcs of all sizes - save their Deatfist Slashed Belt and Orc Scalp
Will-o-wisps - save their Lightstones and Greater Lightstones
Bears - save their High Quality Bear Skin
DF belts sell fairly easily for 5p each to players, Orc Scalps fly off the shelves for 10p each
Lightstones and Greater LS don't sell that well, but you can save them and turn them in for XP instead at the South Ro gypsy camp. Even at level 20 it gives noticable XP, and turning in a Greater LS gives you an item back that you can sell for 10p to the merchant. See
Evil Research quest
High Quality Bear Skins sell fairly easily for 30p each.
It shouldn't take you more than an hour to be at least 100p richer; repeat as necessary!
Another bonus is that you can ask (nicely) for buffs at the EC tunnel (or some people announce that they give them out). Just watch out for wandering Freeport guards and the druids at the druid rings.
Apart from spells, shoot for newbie gear in the 20-100p range per item; use
the gearing guide for reference or look up suitable items yourself here:
http://wiki.project1999.com/Category:Shaman_Equipment