This document provides an overview and user guide for Space CrowdFund, which connects space investors (backers) with space companies and projects. It describes the roles of backers, owners, and partners in space projects, and outlines the process for registering with Space CrowdFund, submitting project proposals, reviewing projects, funding project campaigns, and completing funded projects. The guide also provides examples of how projects may be categorized and tagged to aid in connecting the right opportunities with investors.