How to use commas and paragraphs correctly when writing

[CrimpJiggler]

I want to learn how to write professional looking letters so I have to learn how to use punctuation and stuff properly. As silly as it seems, I still don't know when and where to use commas. I used to not know how to use them at all but someone advised me to sound out the sentence in my head and then wherever there's a pause, put in a comma. That works to a degree but I'm still not fully sure. Let's say I'm writing a letter with this sentence "Hello, I am contacting you on behalf of my client John Doe". I notice there's a pause in between client and John Doe so should I put a comma in there (e.g. "on behalf of my client, John Doe") or is there some other symbol I should use?

I also don't really know how to use paragraphs. I just haphazardly throw them in whenever I feel like it. For example I threw in a paragraph there to make this thread easier to read but the reason I chose that particular place to put it in was because this is my 2nd question. Is that the correct way to use paragraphs i.e. to separate different elements of the text? What happens when you've written a lot but you can't see any logical way to divide it because it all seems to be part of the same element?

 

[diligence]

Ummm, I'm no grammar nazi but your writing looks relatively fine, and this is just a casual message board.
As far as professional letters, the best advice I can give is be as concise as possible. Keep the sentences short. Don't use things like "so" or "be" (like i just did). For instance, when you said "i want to learn how to write professional letters so i have to learn how to use punctuation properly."
Instead, just say "I want to learn how to write professional letters. I need to learn better punctuation."
It sounds better with less "filler". Much of it should be replaced with a period.

 

[Vanadium 50]

Read "The Elements of Style" by Strunk and White.

 

[D H]

Get a copy of Strunk & White. This book is short, sweet, and cheap. The original "Elements of Style," published in 1918, is a bit outdated but is available online. The 1972 edition is in my mind still the best of the several revisions that have followed.

Edit
Vanadium 50 beat me to it by a couple of minutes!

 

[jtbell]

It also helps to read a lot of professionally-written or -edited stuff: magazines, newspapers, books, web sites that aren't simply thrown together by someone in his/her basement. I probably "learned" most of my writing skills this way, and by constant practice.

Style guides and composition textbooks can help you recognize concepts that you sense vaguely by reading well-written material. I think they work best if you have a lot of reading experience to begin with.

 

[CrimpJiggler]

Thanks I'll give that book a read.