Dean:
To fix the chips, the best thing to do is to not try to disturb the OEM paint around the chip. First, clean the whole affected panel you are going to repair wih some sort of degreaser and wipe it off with lint free paper towel.
Buy a 3M sanding pen at an autobody or auto parts store made especially for this, or make up some very small sanding sticks by gluing some #220 sandpaper to small sticks that can sand JUST the chipped area. Sand the chipped area, clean it again, then apply some primer from a bottle using a fine toothpick. Only use a little bit of primer and try not to get any on the existing paint finish, but make sure you cover the chip area fully with primer. If you do get any primer on the OEM paint around the chip, wipe it with a cloth with a little lacquer thinner quickly.
When the chips are all primed and you have waited at least a few hours, then you are ready to apply the touchup paint. What you want to do is apply the paint to the chipped area by a wicking action from the toothpick to the panel and let the paint flow into the chipped hollow which is still lower than the surrounding painted OEM surface. This is especially true for metallic and pearl type OEM finishes because you will never get it to blend if you go outside the chipped area. I am assuming here we are talking about small chips. Only apply enough paint in one go to flood the chipped hollow. IE. once it appears uniformly covered, stop and go on to the next one. Don't worry about the applied paint appearing humped or not flush with the OEM painted surface of the panel. The solvents in the paint will evaporate and leave a very thin paint film. After doing all the chips, wait a few hours and go back and hit them repeatedly like this until you build up the paint level in the chips slightly above the panel surface.
When you are done with the touch-up paint, take some #1800 3M waterproof sand paper, soak it in warm water with a little dishsoap for
10 mins, then fold the paper up into a 1x1" sq and LIGHTLY sand the repaired chips either by bare hand or with a small sanding block, making sure to keep the area lubricated with a wet cloth or spray bottle of soapy water. The goal here is to knock the repaired chip surface down even with the panel so it will disappear and blend right in. Check every 5 or 6 passes with the paper by drying it off and inspecting it to see if it is disappearing. This is sort of scary because the sanding will dull the finish on the area around the chip, but you can restore that easily later. Remember to only sand as much as needed. Your chip repair may not have enough paint in it and still be below the panel's height, so if this is the case, you need to decide whether to stop sanding and then clean and go back to filling it up more with touchup paint, or just stop sanding and leave it if it's good enough.
The final step after sanding the chips is to restore the panel finish with a 3M rubbing compound applied using a soft cloth. Apply it in one direction. Let it dry and rub off with clean soft cotton cloth. You may need to do this 2 or 3 times to bring the shine back up. Then wax and you are done.
Others:
You can sometimes restore a clearcoat finish if it hasn't obviously peeled by a clay bar, rubbing compound, or if necessary wet sanding with #1800 or #1500 sandpaper in this order. For paint that appears dull and oxidized or damaged by tree sap, a clay bar used with a lubricant can actually do wonders to bring up the shine and remove contaminants like sap. I've used one and was pretty surprised. You can buy one with a lubricant at any auto parts store.
If your finish is old and oxidized, and you have tried a clay bar, then I would use a good quality rubbing compound applied professionally with a decent polisher, not these big 9" things sold to consumers as waxers. You may want to get this done by a professional detailer for best results because if you don't know what you are doing with a powerful polisher, you can generate too much heat and burn the finish.
The last resort to restore a finish is wet sanding it. It is not all that difficult but requires a light touch and knowing when to stop because a clearcoat finish has most of its UV inhibiters near its surface. Thin clearcoats should not be sanded at all. When professionals are making a decision, they will use a surface film thickness gauge which can actually measure the tickness of the clearcoat. If you sand too much, it may look great but you will have reduced its durability. As well, if you sand too much and blow thru the clear, you are done. Only way to repair that is by repainting the car. This is why it is a last resort. If the car is old and you don't plan to keep it beyond 2 years, then go ahead.
cheers,
dave mc