a friend of my said : herbalism and mining are the best money makers my only question is very simple

is herbalism a good money maker ?

and for fun :

why is it a good money maker ?

There are several herbs that sell for terrific sums - so yes, Herbalism is a moneymaker.  However, if you are also taking mining, you might find that skinning is easier, as you will at least not have to make further detours off your path to skin critters. 

I have toons that mine, skin, and collect herbs.  All of them do well, but I would find it tedious to always be running all over the map to mine AND pick flowers :)

That's just me though - might not bother you at all.

Best of luck!

Mining and herbalism won't be a good combination, for grinding mats to sell or even send to another of your characters. I would rather go for eighter Herb. or Mining and Skinning.

And why would I do that? It's simple Leather is very easy to get, just go kill, loot and finaly skin, and herb. or Mine, just hit your find herbs or find minerals. ( You can't use both )

For gold grinders who uses their skills while questing, this teknique would give atleast 600 to 800 gold ( Depends AH prices ) before you reach 60, and that's even without drops and quest rewards.

600-800g before lvl 60 is so true.  I skin and herb and i have about 750g at the moment (lvl 55).  Thats after buying my lvl 40 mount and countless weapons and armor from the ah.  If you want a quick and easy way to get gold pick up 2 gathering profs.  I just quest and pick up what i see-no farming...very easy

i have a lv62 skinner /herbalist and i make 400g a day