All of my relationships have been with guys of different races. It wasn't really due to a preference--it's just how things worked out, mostly due to location (not much cultural diversity.)
While I am all for interracial dating (or not... everyone has their own attractions, which I respect), I would try to warn anyone from going into it blindly. The "politically correct" thing to do is to hide one's prejudices, and NOTHING brings them out more intensely than an interracial relationship someone doesn't approve of.
You may find that certain members of your family and friends "don't have a problem" with people of other races... Until you announce that you're dating a member of a race they secretly don't approve of. Some cultures will also only approve of dating/marrying someone within their own race, so while communication CAN help, if someone's parents doesn't like you because you're not (insert approved race here), don't expect it to change. It COULD change, but it's likely it won't, and if you have a lot of contact with that person's family (which can also be cultural), that can be hard to take.
I've dated a couple guys who were not on the "approved" list of a few older-generation family members. I'm a bit stubborn, and I made it clear that if he was not treated well at family events, we would not be attending.
I've also been on the receiving end of this, as the person who was "not approved of", and for me, it depends. If I only had to see the family once a year, I could probably tolerate it. But if it was expected that we would attend family events every week and I experienced mistreatment because of it, there's just no way. This would have been especially true if we had kids.
I had a friend once who, like me, was adopted from Korea. Korean families typically expect that their children will marry only Koreans, and only "real" Koreans at that. Adoptees like us are not seen as being real Koreans, and not even real people (harsh, but very true among traditional Asian culture.) My friend dated a guy from a traditional Korean family who would not even speak to her or acknowledge her when she was in their presence. If she was to say anything to them, they demanded that she speak only Korean (which wasn't happening, since she was raised in the USA and knew only English.) My friend tried to give in their expectations, but ultimately, it didn't work.
I'm a bit more difficult than that. If I ever fell in love with someone from a family who treated me that way, I'd be truly torn, because I couldn't put up with that kind of treatment for long before exploding at everyone involved, even though it wouldn't change anything.