What is the best level to well an item? say if I had a lvl 30 dagger and 55 fire charm what would be my bext chances at a successful well for these items?

for the level 30 dagger you should be level 30 at least, for the lvl 55 fire charm level 55 at least
because monsters will spawn with at least this item level, if your character level is below you would have nearly no chance.

usually, i well items directly when i find them, but if you notice you can not beat wells on a certain level with your built/setup
rather transfer them to a mule account and save them until you can do them.

this one should provide you some helpful information to do wells more succesful:

http://forums.d2jsp.org/index.php?showtopic=18559285&f=272