Welcome to the forum! You can start by using the search button There are many different types of lasers... What kind of laser do you want to build? How much money are you willing to spend? Have you any experience with assembling electronics? can you solder? I could go on and on with questions that you should ask yourself, but I'll leave it at this... Do some research, I'm sure you'll find plenty of info.im a new member here! im really interested at lasers but still I need how to build one. can anyone please tell me where I should start and what information do I need to build a laser? thanks in advance!