Diablo 2 FAQ 1.12 guide

Q: Do lightning rainbow facets work on traps?
A: NO. Traps are minions, therefore they will not receive either bonus, +% dmg or -res, even though it will have no effect, it will still show up in the character screen.

Q: How much MF should I aim for?
A: There isn't a particular amount of MF that is perfect. The more MF you have doesn't necessarily guarantee you will find better items, just more magic items. Therein, adding MF does not make you find better items, and will reduce your killing speed.

Q: What auras do different Act 2 Merc give?
A: refer to this guide
Combat (Normal): Prayer
Combat (Nightmare): Thorns
Combat (Hell): Prayer
Defense (Normal): Defiance
Defense (Nightmare): Holy Freeze
Defense (Hell): Defiance
Offense (Normal): Blessed Aim
Offense (Nightmare): Might
Offense (Hell): Blessed Aim

Q: What are "permed" items?
A: "Permed" items are items that will not 'poof', or disappear. They are items that are from 1.09 or earlier, and are almost guaranteed not to disappear. Items that were duped in 1.10 tend to poof. Beware of people claiming their items are "permed" as people like to try to do this to make you pay more for their item, when in fact, it isn't permed at all, and will poof. Only trade for "permed" items from trusted members.

Q: How can I "perm" my item?
A: There is no known way to completely perm an item. There are temporary perms that will keep your item from poofing until you enter the next game. Although these methods are not proven, these are believed to be working methods. However, you must do these when you leave every game:

Method #1: Initiate trade with another person. Quickly exit the game without saying or doing anything right after you go to the screen.

Method #2 (Different Form of Method #1): Initiate trade with another person. Put the item or items that you wish to perm into the trade screen. Quickly exit the game without saying or doing anything right after you go to the screen.

Thanks to http://www.postabout.com/index.php?s=&showtopic=65480