I am so used to looking up manuals that I tend to forget that the quickest way to learn about something is often through the intenet. Instruction manuals are good only if the subject is highly esoteric. These days, the internet replaces the need for many (but not all) instruction manuals.
One good example is the Photoshop software. When I want to learn to do something new, out of habit, my first inclination is to pull out an instruction manual or click the Help button and then read the steps one by one. Lately I realise that it is far easier to just google for it. You will find lots of lots of help available. Better still, you can usually find a video tutorial, which is like having someone sitting beside you and visually showing you all the steps.
Finding it hard to master Photoshop? Start googling and you'll be an expert in no time. You don't really need to spend money on expensive lessons or buy any instruction manuals.