Need Simple Forum Added To Website

Need SIMPLE customer forum added to website to help reduce need for individually-answered customer emails and create easily-searchable knowledge base. Have seen one done with php that I like that I can give you as an example but am open to format- main thing is that the learning curve for my staff AND customers to use it is as easy as possible. Have established, small retail website. I'm the boss not the techie so please excuse my lack of technical terms.