You can refer http://en.wikipedia.org/wiki/Comma-separated_values
Here is the Basic rules and examples
Any field may be quoted (that is, enclosed within double-quote characters). Some fields must be quoted, as specified in following rules.
Fields with embedded commas must be quoted.
1997,Ford,E350,"Super, luxurious truck"
Each of the embedded double-quote characters must be represented by a pair of double-quote characters.
1997,Ford,E350,"Super, ""luxurious"" truck"
Fields with embedded line breaks must be quoted (however, many CSV implementations simply do not support this).
1997,Ford,E350,"Go get one now
they are going fast"
In some CSV implementations, leading and trailing spaces and tabs are trimmed. This practice is controversial, and does not accord with RFC 4180, which states "Spaces are considered part of a field and should not be ignored.".
1997, Ford, E350
not same as
However, the RFC didn't say what to do when white spaces appear outside the quoted value.
1997, "Ford" ,E350
In CSV implementations that do trim leading or trailing spaces, fields with such spaces as meaningful data must be quoted.
1997,Ford,E350," Super luxurious truck "
The first record may be a "header", which contains column names in each of the fields (there is no reliable way to tell whether a file does this or not; however, it is uncommon to use characters other than letters, digits, and underscores in such column names).
You can also google for more detailed help