IDispose Best Practices...

[elitelogic]

I've searched for info, but I'm still confused. What is the best practice for Dispose() in this scenario and why?

(And what are the code tags? doesn't seem to work.

    class LineReader : ILineReader // derived from IDispose
    {
        StreamReader _file;
        bool _eof = false;

        public LineReader(ref string fileName)
        {
            _file = new StreamReader(fileName);
        }

        // Interface implementation
        public bool AtEof { get { return _eof; } }

        public String ReadNextLine()
        {
            string line = null;

            try
            {
                if (_file.Peek() >= 0)
                {
                    line = _file.ReadLine();
                }
                else
                {
                    _eof = true;
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("ReadNextLine() exception: " + e.Message);
            }

            return line;
        }

        // For IDisposable
        public void Dispose()
        {
            // What is best practice?
        }
    }