Hi L.,
I'm a new mom to a 7 month old and as someone already mentioned (I think) we've found The Baby Sleep Solution book to be helpful. We don't use music, white noise, pacifiers or anything else except a nightlight. I just followed what the book suggests... four feedings a day at the same time, three hours nap time daily (usually one in morn and two hours in afternoon) and most of all NO nap between the third and fourth feeding. Also found it very helpful to put him down sleepy, but not sleeping. This is difficult when he's fussy or just tired and refusing to sleep, but reassuring him and being able to walk out (even closing the door slightly) has made a huge difference -if he does wake during the night he's now able to soothe himself back to sleep without being picked up or us even coming into the room. Of course we have some setbacks, but more or less if we stick to the schedule that day we will usually all sleep that night :) Good luck -I know I need it and I only have one!
Btw, I realize you have the two and both soon to be sleeping in the same room, but maybe some of the above will help with your 5 month old and maybe then overall...