IOS XML Parser for IPhone

I new in XML parsing. I am totaly cofused how many methods we should have to require for xml parsing and what does use of that method.

<response>
    <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">0</int>
        <lst name="params">
            <str name="q">title:ios</str>
        </lst>
    </lst>
    <result name="response" numFound="3" start="0">
        <doc>
            <str name="author">Boney, James</str>
            <str name="author-letter">Boney, James</str>
            <arr name="collection">
                <str>Catalog</str>
            </arr>
            <arr name="ctrlnum">
                <str>(DE-599)BSZ096485965</str>
            </arr>
            <arr name="dewey-full">
                <str>004.62</str>
                <str>004.6/2</str>
            </arr>
            <arr name="dewey-hundreds">
                <str>
000 - Informatik, Informationswissenschaft, allgemeine Werke
                </str>
            </arr>

Now please is there anybody help to find out that, how can i get those informations from the xml data using NSXMLParser or any other xml parser in IOS?

Thanks In Advance.