hi so i just got my n810 and decided to install mer on it. unfortunately when i installed it the first time it didnt go over so well.
i reflashed and installed again. both times i installed using the instructions for the mer bootmenu and mer installer " simple" option. once finished installing it pops up with a message about knowing how to reflash an other thing and asks if i want to continue. i type yes and the terminal window closed, so i rebooted. the boot menu didnt give me an option to boot mer. just internal. i installed mer to internal flash but it still boots to maemo. does anyone have some tips for me?

Well, mer is dead and is no longer being developed.
I suggest you stick with latest diablo plus the community ssu and wait (patiently) for the meego adaptation for the n8x0.

can i ask, what is the community ssu?

i got mer to boot btw... reinstalled the bootloader

http://talk.maemo.org/showthread.php?t=30648

I'd agree with Luca. Latest(last) version of Mer was 0.17, and booted up ok to the desktop, but the graphical environment was painfully slow.

If you have a bit of linux knowhow, and want to experiment, there is always Android 1.6, but it does not dual-boot, and still has a few issues though. Or wait for Meego....