Not a dumb question, at all. But, it's probably going to be answered with a whole range of distances :p (don't think there's any set rule on it )
I didn't really know how far from the hook I placed my sinker .... so I went and looked & measured. I have two rods rigged with slip floats, for minnow fishing use. One had sinker 4" away from hook (tie eye) ... the other had the sinker 7" away from the hook. I think that 4-5" is probably closer to the normal distance used by most, but I wouldn't bet the farm on it :D
I have a habit of using the 4-5" distance, when fishing in a fixed position .... and the 6-7" distance, when drifting or moving around. It's just a personal preference thing ... no scientific backing for it :p
The distance your sinker is, from your fixed float, depends on how deep you want to fish. Just be sure and add in the distance from the minnow to the sinker, in your depth equation
If I know the depth from the surface to the top of any cover ... I usually set my rig so that the minnow is less than 6" from the top of the cover. If I don't know how deep the top of the cover is, I start shallow and gradually move the float up the line, until I start getting bit ... or get hung up :rolleyes: LOL !! Then I adjust it a little shallower. This is mostly in regards to casting with a minnow/float, as I do fish "down in" the cover when in a fixed position (tied up/anchored). And I also tend to use the shorter distance, between sinker & hook, when fishing around cover ... as opposed to fishing open water, where I tend to use the longer distance setup. This is done mostly to limit the minnow's freedom of movement (short distance/cover) ... or give the minnow more freedom of movement (long distance/open water).
... cp