Text link ads might be one way to go. Perfectly legal but if google detects it then it's goodbye pagerank. Same for sponsored blog posts. Even if you do take

Text link ads might be one way to go. Perfectly legal but if google detects it then it's goodbye pagerank. Same for sponsored blog posts. Even if you do take on paid for links and google doesn't realise I doubt you're going to make very much from it. I would suggest you use your site as a marketing tool, both for yourself and projects you're interested in, and be happy with that.