Spend a good bit of time introspecting, find out what you want in the long run, and consider all of your feelings. If you try too hard to logic your way through it, well I found that there comes a natural doubt with logic, as your mind will produce plenty of excuses as to why you -shouldn't- transition, but it can't defuse why something simply -feels- so right.
I've talked with more than a few people about a sense of identity, there is no sure way of really knowing. I find everyone has there own little self-identifying niche. Some people, "have always known" while others (like myself) one day just kind-of figure it out "hey, this all makes a lot of sense for some reason" even others take their time to consider it over the years until they are sure what's right for them. Just, go with what you're comfortable with and don't force anything.
As for myself things made sense in that I dreamed of being a girl, I was never opposed to the idea of possessing female anatomy, and I crossdressed because I felt like it. I just felt 'right' in girls clothes, and I ended up exploring that in explorative social settings (Halloween, parties, etc.) I ended up really liking it, and figuring it was proper for me.
Also, talk to your father, he'll probably listen and/or help in useful ways.
I've never had a problem finding colorful knee-highs at Target, but I'm not sure if that's what you're asking.