How to use picklist field in Visualforce page in Salesforce ?

To show a list of values in Visualforce first create the Apex class :

public class TestClass {
    public String selectedaccId {set;get;}
    List<selectOption> options=new List<selectoption>();
    public TestClass(){
        selectedaccId ='';
    }  
    public List<SelectOption> getListOfAccount(){
        options.add(new selectOption('','--Select--'));
        for(Account acc:[select id,name from account ]){
            options.add(new selectOption(acc.id,acc.name));
        }
        return options; 
    }
}

And then display it on Visualforce page :

<apex:page controller="TestClass">
    <apex:form >
        <apex:pageBlock title="Account Name">
            <apex:pageMessages />
            <apex:pageBlockSection >
                <apex:OutputPanel >
                    <apex:selectList label="Account Name" value="{!selectedaccId}" size="1" multiselect="false" required="true"  >
                        <apex:selectOptions value="{!ListOfAccount}"  />
                    </apex:selectList>
                </apex:OutputPanel> 
            </apex:pageBlockSection>
        </apex:pageBlock>
    </apex:form>
</apex:page>