Thanks for your response and encouragement!

My issue with writing isn't with the mechanics of it (In fact, I'm pretty good at noticing flaws in other people's grammar.), but rather in expressing myself. I think a lot of that comes from simple inexperience, which can be fixed very reliably. I've read other welcome posts for inspiration, but just sitting down and figuring out what to write is hard for me. It might be easier for me to write a welcome post episodically, i.e. posting a small amount, then adding additional small bits of text as I figure out more of what I want to write.