The Data Conversion Handbook, Edited by Walt Kester, Newnes, 2005, ISBN 0-7506-7841-0. Also published as Analog-Digital Conversion, Analog Devices, Inc. 2004, ISBN 0-916550-27-3.The Data Conversion Handbook is written for design engineers who routinely use data converters and related circuitry... www.analog.com
You're on the right track. Yes, the filter cutoff should obviously be higher than your frequency of interest. But you still need to know some other factors, like how much out-of-band attenuation do you need? If it is, in fact, 30 MHz sample rate you could use a 1MHz cutoff. Or 20kHz.