Note: I have very little linux experience, so I prefer solutions like pasting a single command into the terminal and have everything happen automatically, including post-install config ;)
You will get packages ready for most of distributions and the installation is really simple: http://www.mongodb.org/display/DOCS/Ubuntu+and+Debian+packag...
I can create test database with web frontend just to test and experiment a little - please let me know if you are interested (at beta@ninjaci.com).
Do a Google search for one of the many grids available which show which options are best for which cases.
If you want to go with something that is best, most popular, easiest to install, etc, then go with MySQL or PostgreSQL.