In English, the order of adverbs isn't an important consideration. You can say, "Next Tuesday, I'm going to the mall," or you can say, "I'm going to the mall next Tuesday." Emphasis comes from the way we say words in English, and placement in a sentence isn't all that important.
In German, though, things are a little bit different. The conjugated verb (in other words, the verb that changes to suit the subject) always takes the second position in a German clause. The Germans refer to the concept this way: verb an zweiter Stelle (verb in second position).
What does this mean? Well, in a simple sentence this is easy.
English: Dirk is at school today.
German: Dirk ist heute zur Schule. Notice: "today" comes before "at schoo" in the German sentence. We'll come back to this.
What about when there's a helping verb or a modal verb? Remember -- the conjugated verb stays in the second position, while the action verb goes all the way to the end of the clause.
English: Frieda is supposed to eat with us tomorrow.
German: Frieda soll mit uns morgen essen. The action verb, "to eat," goes to the end of the clause.
Where does Time, Manner, Place come into all of this? Well, because the action verb won't come until the very end of the clause, in a lot of cases, the reader (or listener) can get confused as to what is going on, and so in German, you write (and speak) adverbs in the order of time, manner, and place. This includes adverbial phrases, such as prepositional phrases.