It's the example in the Trail:
<apex:page standardController="Contact" recordSetVar="contacts">
02    <apex:pageBlock title="Contacts List">
03         
04        <!-- Contacts List -->
05        <apex:pageBlockTable value="{! contacts }" var="ct">
06            <apex:column value="{! ct.FirstName }"/>
07            <apex:column value="{! ct.LastName }"/>
08            <apex:column value="{! ct.Email }"/>
09            <apex:column value="{! ct.Account.Name }"/>
10        </apex:pageBlockTable>
11         
12    </apex:pageBlock>
13</apex:page>

First I entered it all by hand and it goes to a page with the title but no columns nor data. So I just copied their example and pasted it, still no data on the page, nor headlines, columns, etc. 
What is missing?
Thanks

I have my custom object,with records,i need all my records to be  displayed in my visual force page... when i click on button listrecords...