Are the following independent or dependent clauses? (grammar)?

An independent clause can stand by itself, hence the "independent." An independent clause would be your second sentence. A dependent clause always begins with a subordinate conjunction (although, before, until, since, when, after, because). Be careful, though, because a dependent clause has a subject and verb. It's easy to mix dependent clauses and prepositional phrases, but remember, PREPOSITIONAL PHRASES NEVER have verbs. =]