So, you want to write a tutorial?
If your English is not very good, but you know there is something you want to write, write it first, and get someone else to check it, or just propose a tutorial on the Miranda_IM_Wiki:Community Portal talk page.
Try and keep the steps as simple as possible. If you are describing the text on a button or control, surround it with single quotes 'like this'.
Keyboard shortcuts often help (if they exist) for difficult tasks.
Besides that, go ahead and do it!