i second kerrys idea. my group has spent the majority of our 5 years between jesse and oriana. for the maria/oriana route you have two options, going through hamburg or going through jesse.

the jesse route provides you with some nice fishing opportunities. jesse has darker water and tends to be shallow. white or chartreuse are the colors there, and the numbers of walleyes are great. should easily be able to keep the kids busy. a must visit lake if you have young kids along.

my group never has fished maria or hamburg because we prefer just to make it to oriana the first day with plenty of time to set up camp and whatnot.

oriana is probably my favorite lake in the park. beautiful scenery, the water is more on the clear side, deep, and open. also, what we find important, is that oriana has every species you want in the lake. lake trout, walleyes, smallmouth bass, and pike. sometimes its a bit tricky to find big fish because it is a cisco forage based lake. the larger fish tend to hunt the schools of cisco while the smaller fish 15"-20" range stick to shore and bottom structure. the only issue here is that its pretty open, so if you get a windy week you might struggle with the youngins.

issues you may come across on your route... if it has recently rained, the maria-jesse portage becomes a swamp and the little logs float around. last year(on our way out) they were doing some trail management and dug some drainage ditches, so this may have changed.

if the water is low, the maria-hamburg and hamburg-oriana portages are along streams. with low water the streams are not navigable in your canoe, so they turn into long walks along streams through tangled grass. not overly pleasant for youngsters.

make sure you get yourself a quality map of the whole area. i believe the quetico north central map only goes to the western edge of oriana, so you might need the next map over as well if you are going into quetico lake. its a good idea to make some color copies of the areas you plan to go and laminate them so everyone can have a map, just in case.