I am looking for books that have mages or wizards or alchemists, I have a huge interest in alchemy and herbs etc. also looking for great world building, or books that tell the life story of the mage/wizard/alchemist.

thanks for any suggestions

What kinds of books have you liked/disliked before? That would make it easier to tailor a recommendation to your tastes.

Paulo Coelho's The Alchemist deserves at least a mention, though I haven't read it and I'm not sure how much alchemy is involved.  It's supposed to be good. 

I'm coming up blank when I try to think of alchemists/herbalists, (unless you count non-fiction, or new ageish ) so here's some random generic wizards for you. 

Ursula Le Guin's The Wizard of Earthsea trilogy is generally considered one of the essential fantasy series.  Each book covers a different period of Ged's life.  The first his childhood/training, the second as a mid 20's or so, the third as an old man.  In my opinion, this one is more about the atmosphere and the events rather than the world building.

There's Mary Stewart's Merlin series.  The first is The Crystal Cave.  This is lighter on the fantasy elements and heavy on the historical, but it follows Merlin from his childhood up through his entrapment as an old man.  The world building is good here, though it's mostly just a straightforward historical telling of the King Arthur legend from Merlin's point of view.

The Dresden Files Series-Jim Butcher.

Harry Dresden is a Wizard who works as a Private Detective in Chicago. 

-RD

The Mistborn series by  Brandon Sanderson might be the closest I can think of to meeting all of your descriptions.  It is a trilogy that does a good job of tracking the life of one of the main characters, a street urchin named Vin.  I thought the world building was excellent, and the magic is called Allomancy, and is based on using different metals for different abilities.  For example, people who can use Pewter are called "Thugs," and they have enhanced physical abilities (strength, healing) while they use it.  People who can use tin are called "Tineyes," and they have enhanced senses.  Then there are people who can use all of the metals, they are called Mistborn. 

EDIT: Although, looking at your Profile, it looks like you have the first book on your wish list, so that might not be much of a recommendation : )

thanks everyone for the suggestions,

Davies, i decided to pick up the first book in mistborn today on lunch,

Rob, i also picked up the first book in  The Dresden Files   also.

Melanti, i have read the The wizard of earth sea trilogy, and loved it. I did pick  up  The Alchemist  and The Crystal Cave today also.

So i cant wait to get started on all the suggestions you all gave me.

Thanks !