Bob - I use Tamiya thinner... it has a retarder of some type in it that slows drying time of the paint allowing a smoother finish and seems to make it easier to airbrush, you can get a big bottle of it from squadron.com or greatmodels for about $6.00 and like the needle lube it last forever (well about 6 months to a yr of moderate building) Mine is about 1/3 full still after I'd say 5 kits or more. (it's the 750 ml one)
I used to use the same Tamiya thinner to clean the AB but switched to windex. take your cup off (if you only have one) empty the excess paint back into the bottle, spray windex into it, run a qtip around the walls of the cup then pour out the windex ... use a paper towel to wipe out the excess.
Reload with windex, spray it through at about 40 to 50 psi, remember to backflush in there somewhere (at a lower PSI put a rag or something over the tip and gently push the trigger down, the air will bubble back into the cup bringing with it any more paint inside the body) finish spraying out the rest... when it comes out clear just put some distilled water (89 cents a gallon at the grocery store) in the cup and spray it through and you should be done!
about every 15 to 30 hours of spraying, or if you notice the spray pattern is getting erratic, soak the removable parts of the brush (unless there is a rubber o-ring in there, better check with another paasche H owner first) in lacquer thinner for about 15 min, use a qtip or a microbrush to remove any paint in there and you are ready to go till another tune up!
Good luck!!! Let us know how you like it, I think the next model you do with it will make you one happy man!!! And I'd stick to a plain color scheme the first time or two to get used to it. Something like Tweets maniacal squiggle schemes is something that needs more practice! (and a screw loose or two)