～というと

According to Edict:

1: (Usually written using kana alone) if one were to speak of ..., then certainly; if it were the case that ..., then certainly; if it were a ..., then certainly; phrase used to indicate the inevitability of what follows it (based on what precedes it);2: so that means (when used in sentence-initial position)

Ex. 初恋というと、まずなにを思い浮かべますか。
Hatsukoi to iu to, mazu nani wo omoiukabemasu ka?
When you say "first love", what is the first thing that comes to mind?

You can also use this to refer to your own question:

Ex. どうしてあきらめたかというともうがまんできいなかった。
Doushite akirameta ka to iu to mou gaman dekinatta.
The reason why I gave up is because I couldn't take it anymore.
Lit. If you ask me why I gave up, I couldn't take it anymore.

Reference: Maggie's site

Uses of ほど

Maggie's site gives a nice detailed lesson for ほど. I summarize the basic idea here, together with some expressions that are noteworthy.

ほど indicates degree or extent, and is usually used with a negative verb. It follows the pattern:

A wa B hodo [adjective]-nai.

Ex. Kumiko-san wa Mai-san hodo sei ga takakunai.
Kumiko is not as tall as Mai.

Ex. Kumiko-san wa Mai-san hodo Eigo ga heta ja nai.
Kumiko is not as bad in English as Mai is.

This is the most common usage of ほど. It can also mean "to the level of", as in the following:

Ex. この漫画は、飽きるほど読んだ
Kono manga wa akiru hodo yonda.
I read this manga until I got tired of it.

More interesting, though, are some expressions which utilize hodo.

1. + ば +   + ほど + ....
This means "the more...., the more...."

Ex.  彼のことを知れば知るほどわからなくなる。
Kare no koto wo shireba shiru hodo wakaranai.
The more I get to know him, the more I don't understand.
(Lit. If I get to know him, I will not understand to the point that I know.)

As you can see, it's better just to understand this phrase as a whole. :)

Ex. あの人のことを好きになれば好きになるほど、心が痛い。
Anohito no kotowo suki ni nareba suki ni naru hodo kokoro ga itai.
The more I get to like him, the more my heart hurts.

2. にもほどがある (ni mo hodo ga aru)
"There's a limit to...."

Ex. 我慢するにもほどがある
Gaman suru nimo hodo ga aru.
There's a limit to my patience.
(Lit. There's a limit to how much I can bear.)

Ex. 冗談にもほどがある
Joudan ni mo hodo ga aru.
This is no longer a joke!
Lit. There's a limit to jokes.

3. これ、それ、あれ + ほど
Means "of this/that extent"

Ex. これほどむずかしいと思わなかった。
Korehodo muzukashii to omowanakatta.
I didn't think it would be this difficult.

Ex. それほどお金に困っていたらどうして一言、相談してくれなかったの？
Sorehodo okane ni komatte itara doushite hitokoto, soudan shite kurenakatta no?
If you were that desperate for money, why didn't you tell me?
(Lit. komatte -> komaru -> be in trouble)

How to say thank you in Japanese: ありがとう、感謝する、etc.

Found this. Another interesting page from the same site is on Valentine's Day and 義理（ぎり）. 義理 is a moral obligation to repay someone after that someone gives you a favor, etc.

expressions involving 以上（いじょう）

以上 means "above" or "more than". Sentences from Tanimori's Handbook to Japanese Grammar.

Examples:
18さい以上のひとしか入れません。
18さい以上のひとしかはいれません。
Only those above 18 years of age are allowed to enter.

そこまで行くのに一時間以上かかります。
If you're going there, it's going to take more than 1 hour.

彼は王様以上だった。
He was more than a king.

It is also often used with これ、それ、and あれ.

Examples:
これ以上ここで待てません。
I can't wait here any longer.

それ以上は無理です。
Any more than that is impossible.

It can also mean "above-mentioned".

Examples:
以上の理由でこれは中止になりました。
This was cancelled for the reasons mentioned above.

考える (kangaeru) and 思う (omou).

The difference between the two are summarized in TheJapanesePage. I write it now in my own words. This  is another reference.

考える (kangaeru) -- involves logical thinking; may involve weighing pros and cons over a long period of time; you think with your head
思う (omou) -- involves feeling, opinions; more sudden than 考える; you think with your mind or heart

try to do: -てみる vs. volitional+とする

Although both mean "to try to do something", there are some nuances involved, and the two are not interchangeable. Thanks to Elenkis' post here, I finally got a decent explanation for this.

1. -[te form]+ みる is used when you are trying to do something because you want to see what happens afterwards. The emphasis here is on what happens if you try.

2. -[volitional form of verb -おう or -よう] + とする , on the other hand, emphasizes the fact that you are going to try, regardless of the result. Note that  In fact, a similar construction (-ようとした), indicates failure ("I tried..., but I failed.).

As Elenkis said, there is a difference between  “I’m going to try drinking sake (and see what what it’s like)” and “I’m going to try to finish my homework tonight”.

Other similar constructions are [plain non-past form]+ ようにする. Another is [plain non-past form] +ことにする.

3. [plain non-past form of verb]+ ようにする means that you put your mind on something, and you're going to exert all effort, even if you fail, until you reach your goal.

4. + ことにする means that you have decided on doing something. It can refer to a single or a habitual action. This seems close to the construction  -[volitional form]+と決める（きめる）, as mentioned by Tae Kim, although I haven't heard or read the latter used.

expressions involving わけ

わけ means "reason", and has the same meaning as 理由（りゆう）. In some cases, the two words are interchangeable:

Ex. 日本語を学ぶわけは興味があるからです。
Nihongo wo manabu wake wa kyoumi ga aru kara desu.
The reason why I study Japanese is that I am interested (lit. I have an interest) in it.

In this case, わけ means "reason" and thus can be replaced by 理由. However, in certain common expressions, this is not the case:

1. -る form of verb + わけには行かない

This is used when you can't do something, or when you shouldn't do something. It has the connotation of being powerless to do something (that you may want to do) because it is against your principles, etc.

Ex. だれにもじゃまさせるわけにはいかない。
Dare nimo jamasaseru wake ni wa ikanai.
I can't let anyone get in the way.

Note that this phrase is commonly written in kana only.

2. -ない form of verb + わけには行かない

This is a phrase which I have never heard used, but which is included in "A Handbook of Japanese Grammar" by scholar Masahiro Tanimori (Tuttle Publishing). It creates a double negative, so it gives a meaning that you "must do something".

Ex. 彼女を手伝わないわけにはいきません。
Kanojo wo tetsudawanai wake ni wa ikimasen.
I have to help her. (lit. I cannot not help her)

3. ～わけです。

This can be preceded by:
(a) -る form of verb
(b) な (for nouns)
(c) い (for i-adjectivesadjectives)
(d) -た (for verbs and i-adjectives)
(e) -ない (for verbs)

It means "it's natural that", or "so that's why..."

ex. それで遅れたわけですね。
Sore de okureta wake desu ne.
So that's why you're late, isn't it?

ex. それではたいへんなわけです。
Soredewa taihen na wake desu.
If that's the case, it will of course be difficult. (lit. If that's the case, that's why it's difficult.)

4. ～わけではない。

It means "it doesn't mean". It can be considered the negative of #3 (it's not natural that...)

It is preceded by a verb, an adjective (in i-form or na-form), or a noun + という, giving rise to the expression +というわけじゃない。

ex. そういうわけじゃない！
That's not what I mean!

ex. すべてあなたにさんせいするわけではありません。
It doesn't mean that I agree with you on everything.

It can also be preceded by という. It means that you are denying, though not completely, the sentence that precedes という.

彼女はそんなにきれいというわけではない。
Kanojo wa sonna ni kirei to iu wake dewa nai.
I wouldn't say she's pretty. OR She's not that pretty.


References:
Masahiro Tanimori, Handbook of Japanese Grammar, Tuttle Publishing, 1994
jisho.org (Online Japanese dictionary)
Maggie's site