It's ok. We are here to learn and share! =)
Yup, you can surf EDGE speeds provided that you can get an EDGE signal. (for nokia phones, should be a E near the signal bar)
I think CSD (Circuit Switched Data) is the basic/original form of transfering data on the phone. Like transferring voice data.

GSM data transmission has advanced since the introduction of CSD:

    * High-Speed Circuit-Switched Data (HSCSD) is a system based on CSD but designed to provide higher data rates by means of more efficient channel coding and/or multiple (up to 4) time slots.
    * General Packet Radio Service (GPRS) provides more efficient packet-based data transmission directly from the mobile phone at speeds similar to HSCSD.
    * Enhanced Data Rates for GSM Evolution (EDGE) (E-GPRS) and Universal Mobile Telecommunications System (UMTS) provide improved radio interfaces with higher data rates, while still being backward compatible with the GSM core network.

(from Wikipedia)