Retrieving specific elements from XML document using XSLT

How I could retrieve some specific elements from XML documents using XSLT. In fact, it is a filtering procedure in processing phase to make the input data more calibrated.

For example, for such a document

<catalog>
       <book id="bk101">
          <author>Gambardella, Matthew</author>
          <title>XML Developer's Guide</title>
          <genre>Computer</genre>
          <price>44.95</price>
          <publish_date>2000-10-01</publish_date>
          <description>An in-depth look at creating applications 
          with XML.</description>
       </book>
       <book id="bk102">
          <author>Ralls, Kim</author>
          <title>Midnight Rain</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2000-12-16</publish_date>
          <description>A former architect battles corporate zombies, 
          an evil sorceress, and her own childhood to become queen 
          of the world.</description>
       </book>
       <book id="bk103">
          <author>Corets, Eva</author>
          <title>Maeve Ascendant</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2000-11-17</publish_date>
          <description>After the collapse of a nanotechnology 
          society in England, the young survivors lay the 
          foundation for a new society.</description>
       </book>
</catalog>

Theses results are expected:

<catalog>
           <book id="bk101">
              <author>Gambardella, Matthew</author>
              <title>XML Developer's Guide</title>
              <genre>Computer</genre>
           </book>
           <book id="bk102">
              <author>Ralls, Kim</author>
              <title>Midnight Rain</title>
              <genre>Fantasy</genre>
           </book>
           <book id="bk103">
              <author>Corets, Eva</author>
              <title>Maeve Ascendant</title>
              <genre>Fantasy</genre>
           </book>
    </catalog>

Moreover, how to remove different elements from each record?