I have a passport that is valid until 2015. 2 years ago I was charged and now have a criminal record. We have a family trip planned to travel from Canada to Walt Disney World next week and I just now thought of my record! Will my passport still be good? Will I be able to fly to Orlando? Who do I contact to find out?
It depends what you were charged with. For example, Americans with a DUI are not admissible to Canada, but Canadians with a DUI are admissible to the US. An assault conviction won't exclude you, but aggravated battery will, etc. So step 1 is to see if you have anything to worry about. The link in Annoyed's answer is a great start.
Next, they don't automatically search everyone's record, so in practice this is only going to be relevant if you go to secondary. Most people don't go to secondary, so you could try taking a chance, though I wouldn't. If you're flying, you'll preclear in Canada and then fly there. But if you are denied you will probably lose the cost of your flights and the first night of the hotel, along with anything you prepaid.
Third, if your conviction would exclude you and you wisely feel that risking it at a border crossing is too much, you can spend about $600 for a temporary waiver. As the same link explains, you need to do this well in advance. "Next week" is probably too soon. In your particular case a call to the US consulate or to CBP is definitely recommended.
You could ask the US consulate/embassy (with the risk that you are making them aware of your situation) or a lawyer. Your passport should be good and US authorities would not generally have access to criminal records from all other countries in the world (but might have some agreement with Canada, I really don't know). Some (but not all) convictions must also be disclosed when applying for an ESTA but Canadians don't need one as far as I know.
However, there is a myriad other potential problems that will be difficult to address on this site and a reliable answer is going to depend on your exact situation, e.g. what your citizenship is, whether you need a visa/ESTA to enter the US, with what specific crime you were charged, where you were charged with this crime, whether judicial proceedings are still pending, potential travel restrictions as part of your sentence/parole, etc. For this sort of personalized advice with serious consequences, you should really consult a lawyer.
What others have not touched yet, is that you might not be allowed to leave Canada! Many countries impose travel restrictions on their citizens that have a criminal record, especially of course those who have not yet (fully) served their sentences.
If you leave the country and such are in place against you, you could be marked a fugitive and end up in jail on your return, not worth it. Consult your probation officer (or other relevant authorities), who can probably also help you with the US entry question (I'm sure they get that one a lot in Canada) or at least forward you to someone who can.