and congrats.
You come to the right place/forum for the X5. Many helpful and knowledgable people on here. However, there might be some "nay-sayer" to spoil your excitement, as it seems to be a trend in welcoming thread lately. Just ignore them.
My suggestion:
1. Oil and filter change (if you don't know when it was done last)
2. Sparkplugs
3. Pre-cats O2 sensors
4. Cooling system overhaul
5. Suspension components/bushings

If you want more than 5
6. Pulleys and Serpentine belts
7. Vanos seals
8. DISA valve upgrade kit

I'm sure other will suggest some more.

__________________

00 E39 DINAN S1 //M5 (82k miles)
06 E53 DINAN 4.8iS, born 2/18/2006 (126k miles) http://www.xoutpost.com/bmw-sav-foru...s-my-dslr.html
90 Straman Z32 TwinTurbo Convertible, (1 of 44 ever made) 5 speed, 444rwhp/451rwtq
01 360 Novitec Spider F1 (26k miles)