Why don't you google? There are a lot of info available.
There are general tips for proofing
Read it out loud and also silently.
Read it backwards to focus on the spelling of words.
Read it upside down to focus on typology.
Use a spell checker and grammar checker as a first screening, but don't depend on them.
Have others read it.
Read it slowly.
Use a screen (a blank sheet of paper to cover the material not yet proofed).
Point with your finger to read one word at a time.
Don't proof for every type of mistake at once—do one proof for spelling, another for missing/additional spaces, consistency of word usage, font sizes, etc.
Keep a list of your most common errors (or of the writers you are proofing) and proof for those on separate "trips."
If you are editing within Word, use the "track changes" or "mark changes" function to make your comments apparent to other reviewers (additions and deletions can be set to appear in different colors).
Print it out and read it.
Read down columns in a table, even if you're supposed to read across the table to use the information. Columns may be easier to deal with than rows.
Use editor's flags. Put #s in the document where reviewers need to pay special attention, or next to items that need to be double-checked before the final proof print. Do a final search for all # flags and remove them.
Give a copy of the document to another person and keep a copy yourself. Take turns reading it out loud to each other. While one of you reads, the other one follows along to catch any errors and awkward-sounding phrases. This method also works well when proofing numbers and codes.
First, proof the body of the text. Then go back and proof the headings. Headings are prone to error because copy editors often don't focus on them.
Double check fonts that are unusual (italic, bold, or otherwise different).
Carefully read type in very tiny font.
Be careful that your eyes don't skip from one error to the next obvious error, missing subtle errors in between.
Double check proper names.
Double check little words: "or," "of," "it," and "is" are often interchanged.
Double check boilerplate text, like the company letterhead. Just because it's frequently used doesn't mean it's been carefully checked.
Double check whenever you're sure something is right—certainty is dangerous.
Closely review page numbers and other footer/header material for accuracy and correct order.
