Another characteristic of theses is that they're controversial -- not in the way debates over welfare or abortion are controversial, but they have to be argumentative. A good test to see whether you're arrived at a worthwhile thesis: if a reasonable person can disagree with it, it's probably on-track; if no one in his or her right mind would argue with it, you're still too vague. No reasonable person would argue with you, for instance, if you said "Literacy is important in Frederick Douglass's Narrative." (A tip: avoid the word "important" in a thesis statement; it's almost always wishy-washy.) You need something capable of generating a debate; it has to pass the "Well, duh!" test. You want to be both precise and controversial.
Your thesis statement should usually come close to the beginning of your paper, but it doesn't have to be the very first sentence -- or even the very first paragraph, depending on the length of the paper. Sometimes it's wise to start with something else, the better to grab the reader's attention. But you should get to your thesis statement pretty quickly, so your reader knows where you're going.
Many grammarians insist on a distinction without any historical justification. Many of the best writers in the language couldn't tell you the difference between them, while many of the worst think they know. If the subtle difference between the two confuses you, use whatever sounds right. Other matters are more worthy of your attention.
For the curious, however, the relative pronoun that is restrictive, which means it tells you a necessary piece of information about its antecedent: for example, "The word processor that is used most often is WordPerfect." Here the that phrase answers an important question: which of the many word processors are we talking about? And the answer is the one that is used most often.
Which is non-restrictive: it does not limit the word it refers to. An example is "Penn's ID center, which is called CUPID, has been successful so far." Here that is unnecessary: the which does not tell us which of Penn's many ID centers we're considering; it simply provides an extra piece of information about the plan we're already discussing. "Penn's ID Center" tells us all we really need to know to identify it.
It boils down to this: if you can tell which thing is being discussed without the which or that clause, use which; if you can't, use that.
There are two rules of thumb you can keep in mind. First, if the phrase needs a comma, you probably mean which. Since "Penn's ID center" calls for a comma, we would not say "Penn's ID Center, that is called CUPID."
Another way to keep them straight is to imagine by the way following every which: "Penn's ID center, which (by the way) is called CUPID. . . ." The which adds a useful, but not grammatically necessary, piece of information. On the other hand, we wouldn't say "The word processor which (by the way) is used most often is WordPerfect," because the word processor on its own isn't enough information -- which word processor?
A paradoxical mnemonic: use that to tell which, and which to tell that.
In most house styles, all the major words in an English title are capitalized -- "major" meaning the first word, the last word, and in between everything except articles, conjunctions, and prepositions: A Tale of Two Cities (preposition of gets no cap), "I Have a Dream" (article a gets no cap). If there's a subtitle, the same rules apply to the subtitle, even if it begins with an article, conjunction, or preposition: Authors and Owners: The Invention of Copyright (conjunction and and preposition of get no caps, but article the is the first word of the subtitle). There are other styles; some publications capitalize only the first word and proper names, and there are different rules for other languages. But it's usually safe to capitalize everything but the articles, conjunctions, and prepositions.
Some transitive verbs: Hit (you hit something or someone; you don't just hit); climb (you don't just climb; you climb something); and bring (bring what?). Intransitive verbs: sleep (you don't sleep something; you just sleep); and fall (while you can fall down the stairs, you don't fall the stairs).
There are a few things worth noticing. First, just because something grammatically needs a direct object doesn't mean we actually use it. If someone said, I swung the bat and hit, we don't have to ask what he hit; the direct object ball is understood.
Second, many intransitives might look like transitives, as in She walked three hours. Here three hours is not really a direct object; it doesn't say what she walked, but how long (it's actually an adverbial phrase).
Third, many verbs can be both transitive and intransitive: while ran in the paragraph above is intransitive, the same word is transitive in "He ran the program for two years." Children can play catch, or they can just play. Even sleep, given above as an intransitive, could become transitive if we said He slept the sleep of the righteous.
The only real danger is when you start changing verbs willy-nilly: "We have to think quality" (giving the intransitive think a direct object; you probably mean "think about quality," if you mean anything at all); "I hope you enjoy" (instead of enjoy it).