The best thing I did was go to a AP style baby boutique when DD was a week or two old and get a bra fitting. I ended up with a bravado that fit me great. Of course, it was $$$ compared to the other bras I got but at 2 years old, it is still with me when they aren't (I just use it with target nursing tanks now). I'll probably get another one (maybe two if I get a gift card!) soon for after the baby comes since this one is showing its age (and no, I don't hand wash them either - I did that with my bras pre-baby but not anymore) and now its getting all stretched around during the pg.
That sucks about the meetings. Most of the groups in our area have one Saturday mornings or a weekday evenings because we do have a lot of working moms that come. I'd say at least 50% of the one I attend is working moms. Perhaps call around to baby stores in your area, several of the ones here also have nursing mom meet-ups. Some have lactation counselors lead them and others don't but either way, it is nice to be able to vent frustrations, tell your story and here from other moms who've been there.
The only "prep" I did before hand was to read the womanly are of breastfeeding and a few others. DD was born when they were still on the older edition but I just reread the new version and it is great. The layout is good for finding information quickly if you are desperate for a specific answer in those first few weeks so if you read through it before hand you can be aware of what is there if you need it. And have the number of someone to call whether that is a LLL leader a lc or whatever. I was 100% for breastfeeding, had read a ton, new all the "signs" to look for and was watching the baby, not the clock, but still had a day of panicking that she just wasn't getting the milk she needed and I really benefited from talking someone who could reassure me. My husband tried but I knew he didn't really know anything and didn't trust him :-) Of course, he was right though - my milk did take a while to come in, didn't see real poops until almost day 8 (and never got engorged or felt letdown) but we just kept at it, never needed to supplement, she went on to be ebf for 6 months and at just over 2 years, she is still nursing.