If you have never dealt with printers, nothing will assure a worry free experience for printing files commercially better than talking to your printer well in advance. Preventing mis-understandings and making them well aware in advance of your goals will more than likely prevent 90% of the mistakes. If you do not get satisfactory answers shop around. The printing business is competitive. The best offer both technical savvy and good service.
PDF 1.3 (Acrobat 4), PDF 1.4 (Acrobat 5) or PDF/X-3 (ISO Standard) ? If they accept PDF/X-3, consider yourself lucky. This type of PDF is the most advanced for commercial printing and is expressly designed to assure good color fidelity between systems. If they can recommend specific ICC profiles to use, then even better.
Be aware, not all DTP apps are capable of supporting some of the advanced PS3 or PDF 1.4 features Scribus supports. Unless the printer's systems are using PDF 1.4, this is not a recommended solution.
This can be a determining factor in how you prepare the files. If their RIP is 3015.xxx+, you can be sure their RIP can handle 100% of the features of Scribus. They might not be able to directly answer that, but...
Consult The Pre-Press Notes and you can even take a printed copy of the PDF with you if the has not heard of Scribus. Soon we will have online a listing of printers who support Scribus.