I didn't really have an interest in posting in here but I'll relent, I guess. I don't think gimmepie can really adequately help in that regard, no offense intended. I'm just far more equipped than he is on the matter.
I plan to do gender transition sometime relatively soon, but I guess that definition of 'soon' is up in the air and only known by God herself. There's not really any advice that can cover every person - it's a very tricky thing and relies on what the person themselves consider transitioning. Do they want surgery? Do they want hormones? Do they just want to start dressing as the other gender? No matter the case, the biggest barrier for most is money first and social pressure/issues/etc second. The trans community tends to be one associated with poverty before starting transitioning, let alone afterwards. I believe hormones are covered in New Zealand, but the required psychiatric evaluations aren't covered and they are very hefty prices in themselves, particularly when those specialising in gender are few in NZ and Australasia in general.
But I'd say the biggest issue outside of finances and where the best advice can be given comes with 'passing'. For those who aren't aware, passing means trying to appear as 'authentic' as possible in the pursuit of presenting yourself as the gender you feel you really are. In short, trying to appear as a cisgender person. That's a technical term for anyone who was assigned their gender at birth and still identify as that gender. Doctors called you male and you still stand by that, basically. So you understand the issues for those transitioning who do not look like the typical idea of masculinity/femininity, and the pressure on those involved to confirm and some would say assimilate. This is particularly pushed on those pursuing female gender reassignment as well.
It's a tricky subject. The best advice I can give is that people be aware of the pressures placed on them and go with what feels right. Shaming those for falling into the pressures of appearing feminine or masculine during transitioning just reinforces things. Sometimes people don't want to be trailblazers and take one for the team and I can't say I blame them in the slightest, given that I want many, many surgeries to achieve my goals. At the same time, I praise those who don't go through the rigmarole of trying to appear as cis as possible. They're the kind of people I want to be like but I know I'd be happier doing my own thing.
In terms of real medical advice, a lot of trans people underestimate the length of time it takes for hormones to have realistic effect and are woefully undereducated on the processes that take place. It's a bit troubling.
There are various hormones that are available, since some people do not respond to certain kinds. My favourite piece of trivia is that there is one kind of estrogen hormone that is taken from horse piss. Breasts do not grow instantaneously and they will not likely grow much at all. Penis size doesn't shrink but testicle size will. Your voice will not be altered, that is something you have to work on yourself. Stuff like that is crucial info. But I think most people could do with a decent understanding of the medical trials that are necessary, if only to dispel the common belief that someone can just enter a hospital one day and exit the next day instantaneously altered.