Welcome and congrats on the open relationship. I keep pondering the approaching thing (only from a single perspective) myself. Specifically talking about approaching non-polys or poly-curious people, my only thing would be to ease into and don't put pressure on them or yourselves. Go slow and be patient. And communicate! There are lots of great threads with advice on being poly in general. I know I really enjoyed reading around here when I first came on. Good luck with the someone you're interested in approaching!