There is hope you wonderful mamas, you!! I applaud you for keeping up the BFing even though you want to conceive again.
Exactly a year ago I was in the EXACT situation you're all in and now I have a beautiful two week old baby girl and my 2 y/o DS is still BFing.

I can definitely share my story but the short version (in case anyone doesn't want the long version) is, go to the TTC thread!! There is SO much great info there and you don't actually have to have a cycle and be TTC to post there and get helpful info. There's even a "TTC while breastfeeding" thread!
SO! Last year at this time my DS2 was 18 mos and I had not even a hint of a cycle. Zlich. Nada. With my first DS I didn't have a cycle for two years and it only came after he slept through the night. I knew if I wanted to get pregnant that something would have to change but I wasn't willing to wean.
My sister recommended Dr. Jay Gordon's method of night weaning and I did my own version of that. I didn't go to the phase where you don't pick the baby up.. Since I was doing it to bring back fertility rather than to get more sleep, I didn't need him to fall asleep without being held (so I picked him up when he cried). And by the 10th night he wasn't waking up and crying anymore anyway! This truly is a very gentle way of night weaning and it worked for us without my DS suffering!
After hanging out on the TTC threads I found out about vitex and started taking it. I think I'd been on it three months and nothing had happened and then I learned about MACA!! Good ole' maca! I started taking it and ovulated within a month! I ovulated before my first period but my luteal phase was too short to sustain a pregnancy. Once I had my first cycle I went in for acupuncture and had three treatments. I also started on natural progesterone cream. My second PP cycle had a longer luteal phase but still was too short (9 days). My third cycle I was pregnant!!

I had been wanting to be pregnant for MONTHS so it seemed like a long wait, but when I consider that I was pregnant on my third PP cycle and the very first one that was normal, I guess it was actually really fast! I did have long cycles and ovulated late (day 21 the month I conceived).
I've probably left out some details so PLEASE feel free to PM with any questions! I feel so fortunate to have been able to conceive while BFing and I know how hard it is to be waiting and waiting for your fertility to return! We seem to be a minority because most women get their cycle back sooner than they want!
GL to you all!!

Oh! Forgot to respond to the questions...
Should I start charting? I tried charting because so many women swear by it, but it really wasn't practical for me. It's not necessary but SO many women find it helpful so I think if it's something you WANT to do, then go for it! fertilityfriend seems to be the favorite among charters.
What am i charting? CM? BBT? For the most accurate chart, you chart both.
Since I don't have a cycle yet--when we do start TTC officially, when should
i test? I was thinking something arbitrary like every monday morning.
I'd start trying now because you could ovulate at any time. Having "I hope we make a baby but I'm not freaking out about it" sex is the best!! And I think picking a morning once a week to test is very smart. Cheap pregnancy tests are just as good as the pricey ones. Although I do love the digital ones because seeing the word "Pregnant" is so wonderful!