I have not seen anything on the net to beat a book. There is a good book with "chart size" (large size, can pin up on wall) pictures in colour with proper Schematic diagrams (in English) a corresponding phone chart (in English) ie components marked as D200 etc and a photo of the phone/MB. There are 3 volumes, one for Nokia and another phone (I cannot remember) also a Motorola, Panasonic, Samsung book. etc (probably more) Some pages show the Oscilloscope readings as pictures and the RX and TX route marked in colour. The books are available from the following website (
www.excelldirect.co.uk ) you need to look on the left hand side of their home page under "repair tools and equipment" you should find the books there.