Back Pack and Enhance

Could you give a general explanation of the actual procedure to enhance something and the levels?

I notice in the pack pack there are many items that when clicked upon the "use" and "batch" buttons don't light up... Should I discard those items??

How do I utilize the gems? do I have to assign them somehow??/ what is the step by step procedure?

Look up under enhancing your equipment for step-by-step instructions.

As far as the backpack goes... most of the journals in there which you think you can't use are probably journals used to upgrade your dispatch abilities and you only use them when you're ready to do an upgrade. Just put your cursor over them to see what it is then go to your dispatch skills and look at that skill and you'll be able to see if it's a book used to upgrade that skill once you've reached the required level.