Here is an artifact creature. It is just like any other creature, except that it can be cast with any type of mana.
When you tap this card (that is what the curving arrow stands for) and pay one mana, you can enable Profetic Prism's ability to give you another mana card.
Myrs are one of my favorite creatures. There are all sorts of Myrs in the Mirrodin Block, but sadly none in the Innistrad Block.
Infect is an ability that is found in several Mirrodin Block cards. The rule for poison counters is that when you have been dealt ten of them you lose the game.
Gust Skimmer is an example of a card with a casting ability that requires a specific type of land (island in this case). When a card restricts the type of mana, that ability is only useful when you can play that specific type of mana.
Here are a few tokens.
Here is an example of an advertisement card. These cards come in booster packs and have advertisements on both sides.
