Getting analog signals into the board

Hello to every one, I live in Colombia, and i am developing a
bioengineering device using the beagleboard, for this i need to get
analog signals into the board, i believe i need to use the serial
port, and a ADC, the problem i am having right now, is that i don't
really know if i could use any frecuency. I mean i would like to know
what else i need besides the ADC.
Please any information or web page you could show me, would be big
help, also if you have information about the C funtions i could use
after, it would help me.

Thanks for the time

Santiago

If you want a nice easy prototyping solution then I can recommend using an Arduino to do Analog/Digital IO…

There are different ways to get this analog signal into BeagleBoard.

Firstly you need an ADC (you are in right direction :-)) which
converts the signal into DIGITAL signal.

Expansion Header (EH) : this header on BB only accepts digital input
and got different functionality. So far this is the best way to get
your signal into the BeagleBoard. (SPI. I2C, etc...). i am currently
trying to fix McSPI part of EH.

Kunal