Mark Nodine has put online the beginning of A Welsh Course; since the page was last updated over a year ago, he may have given up on it, but what’s there is still useful:
This course is one suitable for beginners. The main emphasis of the course is in developing conversational skills in Welsh as it is currently spoken (as contrasted with teaching the forms needed for understanding literary Welsh). The material is an indirect descendent of the Cymraeg Byw movement of the 1960s and 1970s. This course does not assume a general proficiency in learning languages, nor any previous background in Welsh. The course is also developed in such a way that it can be distributed either through an ASCII medium wrapped as a setext, or made available in HTML on the World Wide Web.