How can I allow customers to upload pictures?

Hi there, 

I'm interested in allowing customers to upload and submit pictures (of their houses) online so that I can then reply and provide an accurate quote for home services work (window/gutter cleaning)

Yes this feature is possible. In fact you have multiple options.

You can use the file upload field or you can use one of several widgets.

Here's a relevant section of the user guide:

How to Create File Upload Forms