I think it will be easer to get your code running if you use the LiquidCrystal library that comes with the Arduino 0012. lcd4bit does not print numbers, you can add code to do that but because LiquidCrystal prints numbers exactly the same as Serial, its much easer to get working serial code functioning on the lcd.
To get one of the LiquidCrystal examples to run with your lcd panel, you need to make sure that the library is initialized with the correct pins.
Modify the example sketch so the pins number match your wiring:
LiquidCrystal(rs, r/w, enable, d4, d5, d6, d7)
See the the ladyada page you linked above to see which arduino pins are connected to the lcd pins
The LiquidCrystal hello world example sketch is wired as follows:
// LiquidCrystal display with:
// rs on pin 12
// rw on pin 11
// enable on pin 10
// lcd d4, d5, d6, d7 on pins 5, 4, 3, 2
Note that the comment in the example sketch is wrong - the data lines should be d4 through d7, not d0 through d3
When you have the hello world working , add the following lines to setup:
byte minute = 30;
lcd.print(minute,DEC);
If you see the digits 30 after hello world, you are almost there. Modify the sketch in your first post so it includes LiquidCrystal instead of lcd. Remove the all the old references to lcd and replace them with the lcd code from the LiquidCrystal example. The add lcd.print statements as needed, following the model you used in the Serial.print statements.
Good luck!