Looks like you get to "invent" your dept!
Talk to the Rads and the techs about what they perceive as nursing needs for the dept. ESPECIALLY keep dialogue going with the techs and ask for their opinions and ideas alot. Having a nurse in the dept for the first time may be a little threatening to some of them; the last thing you want to do is alienate the techs. Also, learn alot from them. They have alot to teach.
Assess the dept's needs as far as nursing/monitering equipment. If you are doing IR, you will obviously need (if they don't already have) moniter(s) for ECG, Sat, hr, BP, pressure line(s), temp is nice, too. Need defib. Full crash cart. If you do kids (sedations), your crash cart needs to be ped stocked, as well. Assess your dept drug needs as far as what you need to keep available in the dept. (or is your pharmacy close by?) Be sure to keep emergency meds available, especially for contrast reactions.
Will you still be part of nursing services as far as administratively, or will you be under the radiology administration? If you are not under nursing services, make sure they don't "forget" about you in radiology! Make sure they keep you up on changes in nursing P&P's, education, etc. in your hospital.
Make contact with ARNA (American Radiology Nurses Association). They have a great "Standards and Guidelines of Radiology Nursing" manual available, as well as other materials, and invaluable networking, too! See ARNA.net
What types of procedures are being done in your dept? We could give you more ideas if we knew more about what you will be doing.
Hope this helps a little. Good luck! You will love it! Let us know how you are doing....