interesting....
 

This is very interesting to read :D

Since the OP had a little bit of confusion I guess it is better to divide them according to their meaning...just to help him a little bit more.

もらう and いただく=> both mean the subject receives from someone else. The latter more formal than the first one.
さしあげる、あげる、やる=> all mean the person speaking gives to someone else. They are in order from the most polite to the least. In fact the last one as far as I know it is used towards kids or animals.
くださる、くれる=>it means that a person is giving to the one speaking (can be confusing, but it is not "receive" since the subject is always the one giving). Even here from the more polite to the least.

As you can tell by that small list you will easily understand that the use of あげる instead of くれる (for example) will make so that writing the subject can be omitted since the verb itself identifies the subject itslef.

Just learned a new phrase

A　に　（こと）　を　もらったん　です。

A　に　（こと）　を　いただいたんです。
they gave me something

how could I go and say. (I) gave someone something

would it be （私）は友達にお菓子を上げたんです？

Depending on the power relationship between you and the person whom you gave something to:
XくんにYをやった。 (dogs, etc.)
XさんにYをあげた。 (regular people)
XさんにYをさしあげた。 (important people)

Note: I wouldn't use やる unless it's someone you feel comfortable using おれ around. General rule of thumb that doesn't actually explain it perfectly. But I think for someone trying to get a feel for when to use certain things, I think it's a decent guide.

But generally, I would just go with （さし）あげる until you feel comfortable branching out into less polite forms of Japanese. And this doesn't have terribly much to do with whether you're using the plain/polite form with someone.

I'd use あげる or あげます depending on the person I'm talking to, not depending on whom I gave the thing to.

"Kyleくんにお菓子をさしあげた"でしょ？

Might be wrong, but I don't see くん and さしあげる going together very well.

Well, I'm flattered ;) haha

The syntax is correct, but I would not expect you to use anything other than あげる with me.

On a side note, I thought of a good example of what やる can imply when used toward a person.

Recall that （さし）あげる／やる are "to give [a thing]," but also with て-form mean "to do X for someone." For example, if Tom doesn't like daikon, I could say トムさんに大根をたべてあげた。 I ate Tom's daikon for him.

But here's a fun little phrase: 蹴っ飛ばしてやる. 蹴っ飛ばす is like "to kick and make fly." Utada Hikaru has a song called 蹴っ飛ばせ ("Kick it!" or something like that). やる expresses that the receiver ranks (far) lower than you. Together, they say something like (if you'll forgive my language), "I'm going to kick your ass."

Hopefully that illustrates the caution you should have about using やる.

It's perfectly fine to use やる with, e.g., plants: ツリップに水をやった ("I gave water to my tulips")

Here are examples of 〜てやる: “てやる”の検索結果（320 件）：英辞郎 on the Web：スペースアルク
Note the language: "I'm going to kill you"; "When Lucy doesn't listen to me, I hit her"; "Fa shizzle ma nizzle. Let me finish what I'm doing, and I'll hold it down." etc. It's all pretty gruff except for a few examples at the beginning.

Okay i was just clarifying, i thought Kyle said only use さしあげる　to be on the safe side. it probably would've been better to use ーさん