I have NO CLUE: mGalaxy TROUBLE (app path/rom path???)

[MeMe2014]

I am so new to the MAME world. My husband and I are building one at home for the kids and now we have installed mGalaxy to make things run more smoothly. I  can not get past the set up screen. It keeps telling me that my app path and/or rom path are not valid. This is what I am doing:
Open mGalaxy Runway
Select Activate
Select MAME
Choose app path (mGalaxy.exe file)
Choose ROM path (i have no clue, tried a bunch of different files and nothing works)
De-select 'use script file'
Select 'use database file'
Click 'create database'

I get the error that MAME is activated but one of the paths at least is not valid. which will deactivate MAME.

I know I'm not doing the right things but I can't find any specific answers. Thank you in advance for the help.

[mgalaxy]

Open mGalaxy Runway

ok ;-)

Select Activate

ok

Select MAME

ok

Choose app path (mGalaxy.exe file)

Wrong!! This should be the path to your mame.exe !!!

Choose ROM path (i have no clue, tried a bunch of different files and nothing works)

Sorry but I can't help...perhaps have a look on google for: mame fullset?!

Select 'use database file'

Ok..if you create one..or download one from here

Click 'create database'

For this last point (and previous ones), go there: http://www.mgalaxy.com/tutorial_mGalaxy.html, under the 'The MAME case' title!!

[MeMe2014]

Thank you.