mattd2: I notice you're in NZ. There are some significant differences from the US in terms of the law. I've read, for example, that in a lot of Commonwealth countries, you do have the right not to speak if you're arrested, but remaining silent can make you look bad if you go to trial. In the US, that's not the case. Shutting the hell up is your best bet, as it won't be held against you in court, but anything you say "can and will be used against you."
Beer_me_plz: Asking others who've been through the system might give you a general idea of what to expect, but they're not going to know why their situations might or might not be relevant to yours. Lawyers are (usually) fairly expensive, but a good one can be invaluable.
Note that I'm not a lawyer, and I'm just offering my own observations, not legal advice. The most legal advice I'm willing to give is, "Talk to a lawyer." I mean, most of them offer free initial consultations, right? Talk to a few, get a feel for them, pick one who you think you can work well with. Better yet, ask around for recommendations, particularly among people you know, or contact your state's bar association for a referral