Lots of good advice here! I agree, breastfeeding and pumping are such individual topics!
I get HUGE boobs during pregnancy and got even HUGER once my milk came in with my first. I'm 34 weeks with my second. I'm normally a D or DD cup and was up to J/K cup in the first few months of breastfeeding. After my supply regulated around 4 months, I was back down to H/I territory, and then after a year maybe down to F/G, which is where I am during pregnancy. My favorite bras are these, because they are stretchy, comfortable, and can be worn through all stages. (I wouldn't necessarily say they are the most attractive, but this is just one season of my life so comfort rules for now!)
https://www.amazon.com/gp/product/B00UIDJAW8/ref=br_it_dp_o_nS_ttl?ie=UTF8&colid=3OSSCZSXP7NOJ&coliid=I29JUJVTKFQRRF&vs=1Second favorites - straps don't stay up but they are CHEAP and I just use a little bra-converter-thingy to hold them together behind my shoulder blades:
https://www.amazon.com/gp/product/B00O10LW8E/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 (WOW they are on sale for $6.99! Maybe I should get another one!!!)
I've heard that you can get a fancy lingerie store or a good seamstress to convert your existing bra into a nursing bra (and vice-versa). So if you have a bra that you like, but maybe is nearing the end of its life, you could get it converted into a nursing bra or even try a DIY conversion.
Also, I had a vast oversupply with my first, and leaked a lot. I needed pads for sure. I used reusable Bamboobies, which were gifted to me, but they weren't the smoothest under my shirts. I might try something different this time and am excited that there are some good suggestions in this thread!
And I work outside the home, so I needed an efficient double-electric pump so I wasn't away from my desk too long, since my pumping breaks are unpaid. (I had the Ameda Purely Yours, which is Ameda's equivalent to the Medela Pump In Style, I think. Anyway, my lactation consultant assured me it was just as good as the Medelas that everyone else recommended for working outside the home.) And I used that Simple Wishes pumping bra that Ysette9 linked to - also a gift. I remove or unbutton my shirt and put it on over my regular nursing bra, then get to work pumping (I pumped in a really nice bathroom where I didn't have to be near a toilet and could lock the door for privacy.)
My secret weapon was a pair of Lilypadz. These saved my sanity. I was leaking so much and had such huge boobs that I *HAD* to wear a bra 24/7, and I was getting sores around my ribcage from bra bands chafing there. I was desperate to sleep without a bra, but didn't want to change my bedding every night and risk ruining our mattress, so I got these silicone sticky thingies. They stick directly to your boobs and trap the leaking milk against your skin, when they allow leaking at all. I have also worn them with a fancy dress when I wasn't nursing but the dress wouldn't easily accommodate a bra (to keep my nipples, um, retracted). They come in regular and large size. These were seriously my miracle product. I would just wash them out each morning and let dry during the day, then wear them again the next night.
https://www.amazon.com/LilyPadz%C2%AE-Reusable-Silicone-Nursing-Single/dp/B005DEVVBU/ref=pd_sim_75_5?ie=UTF8&dpID=41XoYY-IKFL&dpSrc=sims&preST=_AC_UL160_SR118%2C160_&psc=1&refRID=31XZXD2VAKXPJ82H3RVGI pumped twice during the workday, or on occasion three times. When my son turned one and started getting whole milk (daycare didn't allow BM after age one), I dropped down to once a day. It was more for myself than for him (to keep pressure from building up at work), although I did end up needing all 200 spare ounces in my stash when I got the stomach flu and couldn't provide even a drop for him (my supply bounced back to "adequate", but I never had oversupply after that). He weaned at 15 months.
I started pumping maybe week 2 or 3? I can't remember. But I wanted to build up a good stash for daycare and get him accustomed to the bottle. I think we introduced the bottle around 6 weeks. My family members loved having a chance to feed him and I didn't mind a chance to get away for some privacy - I would pump while my mom fed him, and read a book or something fun.
Good luck!