I'm with whoever mentioned having comma issues. I've had people tell me I'm a comma nut...that I over use them. In my mind, I seem to think I need them. 
But...thanks to Google...I found this site that explains 21 rules of comma usage, and also gives examples. The site also has a drop down bar, on the right, which allows you to look at other punctuation rules.
http://www.grammarbook.com/punctuation/commas.asp
Oooh, you just saved my life! Well, not literally. I think you rather saved my stories! LOL! Thanks!
Oh and thanks RokOfAges75 (I forgot your name) for the help. I think I get the "I look to you" rule, even though I had to think about it for a few minutes. It is pretty confusing.
I never use text-speak in fanfics. I will never write something like: "OMG! What happened here?!" Then I will write "Oh my God!". Same for wtf (or wth), btw, tbh, idc.. etc. Though I don't use idc that often. I only use them in conversations on MSN or in texts (even when I'm texting in Dutch I use things like wtf and btw. I can't live without English lol! But that's also part of the language of the "youth").
I'm also relieved to know that prepositions is a common issue. I remember my English teacher explained the rules a thousand times but still I got confused.
Oh, talking about shorts. Once, I read a fanfic with something like, "LOL! That was funny, man!" Nick said. "LMAO! I know, right?" Brian replied. I mean, do people actually say LOL and LMAO in real life? I've seen (Na-ah not I seen) a movie once where a girl was like "OH EM GEE!". It was the first time I heard someone actually say it so I thought to myself "why not say oh my God?". But yeah, if I see a fanfic with OMG, LMAO and stuff, I skip it automatically. That's a big no-no!
