s.Select(Func)Func is an arbitrary element function
s.Where(Func)Func is a predicate element
s.Distinct()Removes duplicates
s.Take(int)
s.Intersect(Sequence)
s.Union(Sequence)
s.Concat(Sequence)
s.OrderBy(Func)Func is key selector
Operators that return an element
s.Aggregate(Func) , s.Aggregate(seed, Func)
S.First()
S.Last()
S.Max()
S.Min()
S.ElementAt(int)
s.Single()Returns the only element.
Predicates (return boolean)
s.Any()Returns if there is at least one element
s.Contains(element)
Operators that return an other type of object
S.Count()
See the extension methods in the generic interface System.Collections.Generic.IEnumerable<T> and, even better, in the static class System.Linq.Enumerable
