The aim of this note is to acquaint students, who want to participate in mathematical Olympiads, to Olympiad level inequalities from the basics. Inequalities are used in all fields of mathematics. They have some very interesting properties and numerous applications. Inequalities are often hard to solve, and it is not always possible to find a nice solution. But it is worth approaching an inequality rather than solving it. Most inequalities need to be transformed into a suitable form by algebraic means before applying some theorem. This is what makes the problem rather difficult. Throughout this little note you will find different ways and approaches to solve an inequality. Most of the problems are recent and thus need a fruitful combination of wisely applied techniques.