and ct" will change everything up to the double quote. Great stuff.
E.g:
- ci" (change inner double quote) will change (delete and put you in insert mode) the text between to double quotes.
- ca" (change _a_ double quote) will change the text and the surrounding double quotes.
There are text objects for quotes, brackets, sentences, blocks, etc. There are also plugins that create text objects such as arguments (to functions) in programming languages.