Not a lot and not too long? Sorry to be so cryptic but it kind of depends on the size of the chips. TBH I have found that the oak chips can sometimes leave a sawdust taste. Also, don't count on a ton of depth of character from the chips because they are simply too thin.
Start with maybe 1/2 ounce for a week - taste it and go from there?
I switched to oak spirals a while ago and never looked back. They are very predictable - and there's a certain comfort in predictability. Plus, you can age way longer and get an AMAZING depth of character. I broke a medium toast oak spiral in half and put it in a mason jar filled with rum. Not only do you end up with an awesome rum soaked oak spiral for your beer but you are also left with a rum that is basically a bourbon now! I haven't aged in bourbon yet. I only buy the good stuff and don't want to risk it! lol
I soak mine in the appropriate spirit for a couple weeks (while fermenting) and then transfer the spiral to a second carboy for a period of time 'til the flavor is to my liking.
I have poured the soaking spirit in to taste also.
For Drom John's Innis & Gunn Original, a Scottish Ale
In version I, I used 3 oz Oak chips medium toast soaked in 140 ml Wild Turkey 101, dumped all in the bottom of the primary for two weeks, then bottled.
In version II, I changed it to 4 oz Oak chips American light toast.
I preferred version II.
The spirals look interesting. The last time I tried this a friend thought is was the best beer I ever did. My son almost spat it out and asked me what did I do horribly wrong.