So far, my list of things to look into includes:
TN visa - I will have support from the company throughout the application.
Social security number - I will apply after receiving my TN visa.
Nexus - application sent
US bank account - I will likely use the US branch of my Canadian bank to make transferring money to myself easier.
EZ pass - My commute includes a toll road. I will apply once my US bank account is set up.
Cell phone - One Canadian network (not the one I currently use) gets service in half of the office. I'll have to decide whether I want to stick with a Canadian service provider and risk having spotty reception, or switch to a US plan, but I haven't made it far into my research and I'm open to suggestions!!
Taxes - I have a friend who is a tax accountant and can point me in the right direction for someone who specializes in US tax. Yay!
Travel health insurance - I'm not sure if this is something I need, but I know the healthcare system is entirely different and want to make sure I'm prepared in case of an accident or emergency. Open to suggestions!
So for those of you who also commute across the border: What things did you do to prepare for working in a new country? What things did you wish you had done? Do you have any other advice for me?
I'll address a few...
US bank account - as another suggested we found TD Bank to be good because of their 'cross-border banking' and ability to use a TD ATM in either country fee-free.
EZ Pass - you do not need a bank account to have an EZ pass - there is an option to pre-pay with a credit card (though its less of a hassle to have it linked and automatically re-fill)
Cell-Phone. Compared to Canadian plans, US cell phones can be had for cheap. We had a US number with the US+Canada plan, unlimited texting and calling for $30/month. now that I no longer live in Canada my plan is $20/mo
Taxes - by law you must file taxes both with the IRS and with REvenue Canada. Since there's a tax treaty between the two countries most or all of the income earned in the US will not be taxed by Canada, and vice versa. THe exact amount depends on your tax situation and whether you can meet either hte bona-fide resident or physical presence tests.
Health Insurance - check both with your job in the US (do they offer employer sponsored health care) as well as your province. in Quebec we were not covered if we spent more than two consecutive weeks outside of the province or more than 180 days per year. Any care we got in the US within these confines would be reimbursement only (potentially very large out-of-pocket expenses) and not all reimbursement rates would cover charges from US hospitals.
Because of the two-week limitation we carried additional insurance to ensure coiverage when we were in the US. Since each province's health care system is different I would first determine what limitations it has.
It sounds like you are thinking things through here and taking appropriate steps.
not sure what your living situation will be like but I'd also look into getting a mailing address in the US (a PO box if nothing else). Surprisingly your credit history doesn't automatically transfer across borders, so you might want to get a secured Visa to establish some credit history in the US, which will come in useful should you continue to live and work there (for example, it will make it easier to rent a car in the US if you have a US credit card)