To make it short... machinarium does everything right an adventure game can do right. The games is marvelously beautiful, thrilling and captivatingly told and the riddles are well balanced and suit every situation right.
So go, and PLAY THIS GAME and once you're stuck, come have a look at my solution aka Walkthrough you will find under this introducing but not too long paragraph.
Well, to be precise, below you can find just the overview over chapters of the Machinarium walkthrough, you have to click on the correct chapter of the solution yourself, but you will find it, I'm sure. It should be best to choose the chapter you are stuck in.
If you miss the right chapter fear not, you can use the menu on the top of every page of the machinarium Walkthrough and the huge arrows at the end to navigate through the solution.

And don't forget to scroll deeper, there is even more than just the Machinarium solution on this very page, there is an items list, a collection of concept art of Machinarium (sketches from the developers) and some more stuff to discover...

Solution

more...

Wait, this isn't all yet, there is more:

    All the items listed

    machinarium trivia

    Concept Art/Sketchbook from Amanita Design

    The solution as a .txt file