i love trolling for white bass- especially w/ my kayak - seems the motion of paddling really sets them off and I'll hook double the number from the kayak than i do from my boat. That said I usually start with two lines - one pet spoon and one mepps #3 (silver agila) - if i'm not getting hits consistently i'll swap one of those out for a deep diving shad rap or different size mepps. I do occasionally try others - but those have been my consistent producers so i'll always have at least one of those.
To the points made above though... just trolling is pointless - you need to troll with a plan to hit in/around points, drop-offs, and structure where the fish may be. Time of day & weather also impact what areas will produce.
With that said trolling is a nice way to be on the water with a bit of movement to keep the bugs off. One of the reasons i do it some much on my kayak is that I can fish + paddle at the same time... so catching fish is somewhat secondary (though not entirely
). Trolling with a plan is a good way to find out/figure out the pattern that fish may hold on the lake - especially in a slower boat (though you probably won't catch as many as if you knew exactly where to target).
To your specific questions above - i've already mentioned lures.
I usually run one line braid and the other mono/flouro - the braid is used for deeper diving baits (since more likely to get caught on structure... at least gives me a chance at getting it back). I've found that the mono/flouro sometimes does make a difference - probably due more to how it impacts lure movement than the visibility. Line weight is anything from 10lb to 20lb - you could technically go higher - but i double up w/ finesse fishing when i'm not trolling + i set my drag on the lighter side to avoid line breaking (haven't had a fish break off in over a year yet). You do have to watch your line for fraying.
Speed/length/lure weight are all inter-related - and will be determined by how deep i want my lure. speed is usually 2mph to 3.5 - sometimes rarely close to 4mph (usually when they are schooling with top water action - when i do find a school like that i usually just stop and start casting). the slower/more line you have out the deeper you lure will go (within limits). The flip side of this is depending on how active the lake is you may NOT be able to let out as much line as you like.
Last tip - when trolling - WATCH YOUR DRAG - you want a lighter drag set - when a fish hits you are setting the hook with the movement & weight of your boat... if your drag is set to tight all you'll end up with is fish lips w/o the rest of the fish - which leaves you w/o a fish and a fish w/o a pair of lips (and dead).
hope this helps - just practice & be prepared to lose some lures and you'll start to sort it out.