There is more to the first service than a mere oil/filter change. Let's talk about the oil change first. Go to Sears, or wherever else you choose, and get a good set of metric hex (allen) sockets. I would also recommend that you get a small torque wrench if you are not familiar with this kind of work. Easy to overtighten the drain plugs and small screws. Also stop by the dealer (also available on eBay and from SpyderLovers sponsors) and get the o-rings for the filter(s) and the tank strainer, and the crush washers for the tank and engine drain plugs. You may not use them, but you want to have them on hand if necessary. Saving the receipts for the filter(s) oil, and parts will be documentation that you did the oil change, in case of warranty questions. Record the date and mileage/hours, too.
When changing the oil, you need to also remove the tank strainer and clean it. Inspect the o-ring, and replace if necessary. You will need a new clamp for the hose. A worm clamp of the correct size will work, although I used an Oetiker clamp like the stock one. Also clean the engine drain plug magnet. If there are large chunks of metal, save them to show the dealer. Inspect the filter o-ring(s) and crush washers, and replace if necessary. Be sure to lube the o-rings with a drop of oil or silicon grease when reinstalling. The crush washers can be re-used if not indented badly, or deeply scratched, or bent. I recommend torquing all bolts and drain plugs...especially if you are new to this work.
In the Owners Guide, there is a list of items to be performed at this service. They include greasing the front suspension fittings, belt adjustment, checking BUDS for fault codes, and installing any updates. With the right tools, or by removing/loosening the trunk, you can do the lubrication yourself. Some install right angle or 45 degree fittings at this time, to make future lubrication easier. You will need synthetic greas from the dealer...or an equivalent.
You can adjust the belt, but you will not have access to the correct tool. A Krikit II from NAPA makes a good substitute, but you will have to guess at the right tension. The correct procedure involves jacking up the Spyder. A Krikit reading of 130-175 would be in the ballpark when the tire is on the ground. Unloaded it should read lower. Twisting the belt at the center gives a balpark idea, too. 1/4 turn (not easy) with your finger and thumb is about right when the Spyder is sitting on the ground. If your Spyder is one that the service bulletin for belt retensioning applies to, it may be best to let your dealer do this. If he does, this is a good time to get a basline Krikit reading and try the twist test. Any belt tension adjustment will require belt alignment.
The BUDS hookup needs to be done by the dealer. I recommend it the first time around, even if you have had no problems. It should not take long or cost you much. If there are updates or service bulletins that apply, it could take longer, however. Have the dealer give you the BUDS printout, if he is willing.