Some free useful tools to sign PDF, word contracts online that have the same legal validation as a handmade signature.
Concord , they have a free unlimited plan to sign contracts, does not import from google docs, but you can create templates which is really useful. http://www.concordnow.com/.
Sign Request, also with free unlimited plan, and with google docs (saves docs), easy to use interface. https://signrequest.com
eSignly, free unlimited plan, not that nice UI https://www.esignly.com/
Hello Sign, I was using the free plan until now but limited to 3 documents per month… not enough… the google docs integration is excellent. https://www.hellosign.com/