A CHAR and TINYTEXT column can only up to 255 characters.
A TEXT column can hold up to ~65500 characters
A MEDIUMTEXT column can hold up to ~16,000,000 characters
A LONGTEXT column can hold up ~4,000,000,000 characters.
TEXT should be sufficient for your needs.
You can store most characters in a TEXT column, and if you're using the PHP scripting language, you can use built in functions like ln2br() to convert line breaks to HTML <BR> tags.
See http://www.mysql.org/documentation/mysql/bychapter/manual_Reference.html#Column_types for all the column types.