Welcome to the forum.
I have a '96, which is a bit different than yours, but many of my pictures will be very similar to your vehicle.
I bought my '96 in '99 with just under 38K miles on it.
It now has just under 180K miles on it.
I had the transmission replaced at about 100K miles.
Lower intake manifold gaskets last spring at about 170K miles.
For the power steering, you can change the fluid.....I believe your year calls for Mercon automatic transmission fluid.....do NOT use generic "power steering fluid" that you will find in auto part stores.....
Windstars are known for cooking the power steering fluid,....even with the power steering fluid cooler.
I would get some synthetic fluid.....such as Mobil 1 ATF.
It will say Mercon V and Mercon on the bottle....Mercon is being discontinued....and soon Mercon V or ATF that has both on the label is what will be available.
Don't over fill.
If you are getting a squeek sound when you turn the wheels....it can be caused by dry tie rod ends or ball joints.
They do not have grease fittings....but some of us have gotten grease into them with a grease needle.
You can buy a grease needle at autozone and other auto part stores.....it clips onto the end of your grease gun.
Then you poke it into the rubber boot over the tie rod end or ball joint and pump a SMALL amount of grease in.....the grease comes out faster than one would think......
It is not as good as getting it in through a grease fitting.....but short of replacing the joint with an after market part (such as moog) with a grease fitting.....it is the best that you can do.....and will add life to the suspension joints.
It only needs to be done at most 1 time a year.
For your transmission, Use Mercon V ATF.
Change it out at least every 30K miles.
The windstar transmission is a weak point....so keeping up on the fluid changes is super important.
An auxillary transmission cooler is a good investment.
As a side note.....the radiator fans have 2 speeds.....I found that my fans did not have low speed....just high speed......There is a low speed dropping resistor that had gone bad......I have pictures of it posted.
This is important in keeping not only your engine cool.....but the transmission and power steering as well.......
The fans will be ON at low speed whenever the A/C is engaged (including defrost mode) and the vehicle is not moving above a certain speed (something like 30-40mph).
If they are not....you might check into that resistor.
At this point.....your vehicle is going on 7 years old.....and it is a good time to change out all the fluids.
For coolant.... I think your year calls for Motorcraft "Gold" which is just like Zerex G-05.
The Prestone "all makes all models" is a Dexcool clone.....as are the coolants that will say someplace on the bottle "silicate / phosphate free".......which are not what FORD specifies for the vehicle.
READ the label on the bottle....don't rely on auto part store clerks......as I got told the wrong information at several stores before I found the right stuff.....I had done a lot of research online....so I knew what I was looking for.....and which brands did not carry it.
The instructions for doing a disk brake job have you do the brake job without bleeding the brake lines.
It is a very good idea to bleed some fluid at each wheel every year or so....as it get very dark at the wheel.
You have already seen the post about the P0171 / 174 codes..... Bookmark this website for all the information you will need
http://leckemby.net/windstar/windstar01.html
If you start needing to add coolant, take a oil sample and send it in for testing to make sure that coolant is not leaking into the engine oil.
A visit to this website will get you set up with a free sample kit and instructions...
http://www.blackstone-labs.com/
The most common causes of coolant leaks into the engine are lower intake manifold gaskets and the front cover gasket (aka timing cover gasket).
The head gaskets are not high failure on your year.
For good prices on dealer parts.....
http://www.trademotion.com/partlocat...?siteid=214072
Include your VIN with your online order to help make sure that you get the correct part.....in case of mid year changes.
They will display the list price and their price.
I have had good service from them.
For good information on tires and brakes....
http://www.tirerack.com/
I have had very good service from Michelin Harmony tires.
For tune up.....use double platinumn spark plugs.....which are available under the Motorcraft and Autolite brand names.
This is with the platinumn on both the center electrode AND the ground tab.
This is due to the fact that the spark plugs on 1 side of the engine fire with a positive voltage....and the spark plugs on the other side of the engine fire with a negative voltage.
The Bosch spark plugs that they have on display at many auto part stores....with the 2 or 4 ground tabs are NOT the correct plug for the windstar application.
Read through posts here, and learn what can fail.....so that you can hopefully take preventative measures.
Take note that 1999 was a major change year.....so the 1995-1998 windstars have some major differences.
1 major difference is that the 1999 and newer have a totally different upper intake manifold....which is the one with the TSB for the mentioned codes.