How to serialize in a XML a custom IEnumerable?

Question

I've created a class which derives from IEnumerable<T>. T is a OQTemplate, and this one implements IXmlSerializable correctly. But I don't know how to implement the following class.

public class OQTemplateCollection : IEnumerable<OQTemplate>, IEnumerable
{
    private readonly List<OQTemplate> entries;

    public OQTemplateCollection()
    {
        this.entries = new List<OQTemplate>();
    }

    public OQTemplateCollection(IEnumerable<OQTemplate> source)
    {
        this.entries = new List<OQTemplate>(source);
    }

    public void Add(OQTemplate qt)
    {
        entries.Add(qt);
    }

    public IEnumerator<OQTemplate> GetEnumerator()
    {
        return entries.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }

    public OQTemplate this[int index]
    {
        get { return entries[index]; }
    }
}

I'd like just to have a XML like this:

<OQTemplateCollection>
    <OQTemplate ... />
    <OQTemplate ... />
</OQTemplateCollection>