Buffs, in WoW you are able to get a few buffs by yourself, even without being in a raid. Being an alchemist or a cook helps a lot, but there is always something called the Auction house. There are 5 kinds of buffs you can use, let me explain them briefly.
These buffs benefit one or two things your character needs. For example, “Great Feast” will boost your stamina, attack power and healing power. There are tons of different food buffs, One gives your crit, the other one gives you more haste or expertise. (if you lack the expertise or the hit cap, you can use a food buff to temporarily increase it.) The best part of food buffs is that they stack with everything else.
Since there are two types of elixirs you have to be careful not to buy two of the same kind. Back in vanilla WoW you were able to use as much elixirs as possible, but thank god they changed that back in TBC. You can only use two, but two different ones.
Pretty much the same elixirs as the battle ones, only increasing other stats. These elixirs can also temporarily increase your power, like 3minute armor buffs.
The most expensive of all buffs, usually because of all the mats that are needed to create one, but they benefit starts greatly It’s a shame you cant use Elixirs and a flask at the same time, but it also cuts the costs of raiding. J Flasks for example give you 120more attack or healing power for 2whole hours. And if you die, the buff will remain, instead of vanishing just like the Elixirs and food buffs do.
Yes, they do work. Although not all scrolls are as useful as you, for example the intellect scrolls are only useful when there isn’t a mage present. But armor or agi scrolls might be very handy when you want to increase you dps.