I'm glad you asked! We've all had to decipher things too. I find some of the abbreviations annoying, but I think it's part of the reality of people working on their phones and trying to save space. You'll also note some new people keep their questions so brief that there's no real info - but they think they have to do it in 140 characters. (They don't.)
A couple of other hints - it's helpful when people use paragraphs and punctuation, especially on more detailed posts and answers. People also shy away from using their kids' names, so they'll either use A, B and C or make up clearly fictitious names like "Petunia" or "Fauntleroy." It's a way to protect kids especially if people are using their real names and cities.
If you like an answer (either o your question or to another question you are following), you click "send a flower." You can't reply individually on the main page, so you can either comment in your SWH section if it's important, or message someone privately. You cannot "flame" people though - so don't call someone out by name if you're going to be highly critical. Clarifying their question or thanking them is fine. Usually, people just write, "Thanks to all" or something like that.
If something is questionable, report it. Usually those are spam/troll posts or people trying to get free advertising or lead you to a website of theirs. Sometimes they are obscene. The moderators take care of those pretty quickly.
Also, do go back and look at responses you've already read - if they are substantially edited, the responder will add "ETA" for their edits, but you won't get a notification from Mamapedia as you do for new responses. You can miss helpful information if you don't go back and check. And if you see stuff repeated, it's just because the site was slow to upload and the person clicked "post" more than once, so the info is repeated!