Get a list of distinct values in List

Distinct the Note class by Author

var DistinctItems = Notes.GroupBy(x => x.Author).Select(y => y.First());

foreach(var item in DistinctItems)
{
    //Add to other List
}

Notes.Select(x => x.Author).Distinct();

This will return a sequence (IEnumerable<string>) of Author values -- one per unique value.