Before you use this guide realize it tells you everything about how many essences you will need and which runes to make! So if you would like a little excitement yourself just go try it out!
Anyhow... You will need to find yourself at the skilling area (click the skilling teleport, in place of where Ardougne Teleport usually is), and the three places you need to know of are the bank there, bob, and the mage of zamorak. The bank and bob are located in the building in which you teleport in front of, the mage of zamorak is located in the building just west of it (range shop in runescape).
To practice this skill, you will take "rune essences" that are not noted to an altar of the corresponding rune you wish to create and enchant them. The mage of zamorak will teleport you to any altar and all you need to bring is the essences in your inventory. Then craft them by clicking on the altar.
You must purchase your rune essences from bob, for 4 gold each, in order to achieve 99 runecrafting you will need 1148 essences!
As for which runes to make for the fastest 99, it will go as follows, in the order shown:
-28 air runes (1 inventory)
-28 body runes (1 inventory)
-28 cosmic runes (1 inventory)
-28 nature runes (1 inventory)
-84 law runes (3 inventorys)
-784 blood runes (28 inventorys)
Then you have 99 runecrafting!
As a note, you may notice when crafting the blood runes that you do not need to teleport to an altar, just make the selection from the mage of zamorak and your runes are crafted right there! Also, this is probably the easiest and fastest 99 to get!
Happy Crafting =]