Default selection for <f:selectItem> within <h:selectOneMenu>

<h:selectOneMenu id="items" value="#{bean.selectedItem}">
  <f:selectItem itemLabel="10" itemValue="10"/>
  <f:selectItem itemLabel="20" itemValue="20"/>
  <f:selectItem itemLabel="30" itemValue="30"/>
</h:selectOneMenu>

The default selection would be the one which has value same as selectedItem which you set in bean.

selectedItem = 20;

Initialize the recordsPerPage in your backing bean.

From your source code I assume that you have a bean FileSearchCriteriaOut and your recordsPerPage is a String, then you can do the following in the bean's constructor:

public FileSearchCriteriaOut() {
   recordsPerPage = "20";
}

For the facelet refer to Jigar Joshi's answer.