battery disconnect?

[der BMW]

I just got my new e36 and have to replace the battery. My question is, once I reconnect the new one are any lights gonna come on in the dash? Also, I still have the stock radio (am getting a new one in a few weeks), and I heard that it requires a code to turn it on after the battery is disconnected. The BMW dealer refuses to tell me what it is so can anyone give me a little advice from their own experiences with this? Thanks.

[Bimrpwr]

you will have to reprogram your radio, time, date and thats about it. What you can do is buy this $15 dollar part i seen some where and you plug it into the cig lighter to keep all your programming.