Here’s a little more information for you.
If all you need is a simple contact form, you can use SPForm. It’s not in the repository yet but you can find it here:
http://modxcms.com/forums/index.php/topic,19357.0.html
For more information about snippets, chunks, etc. and how to use them, look here:
http://bobsguides.com/MODx.html
The site is far from finished and I hope to have more information there about specific snippets eventually but it will give you another overview of how MODx works.
ProWesbscape’s approach in this thread looks good to me. Make sure that the "container" checkbox is checked on the blank documents that will be containers for your content documents (e.g. the Members page and Research page). Also, be sure to use backticks rather than single quotes to delimit any snippet parameters.
Bob