Well you came to the right spot my friend. First off if you have the make and model of your engines you can go online to the different manufacture's and download schematics of the units. These usually have directions for lube and oil jobs. If they don't then try contacting the company directly. Kalmbach has 2 books on repair and maintenance of Steam and diesel engines both run about 17.95 new or you can try Ebay. If you have older locos you should probably clean the gears to remove old oil,grease & dirt that has accumulated.Don't be affraid to clean lube and oil on your own. Thats the fun of doing it yourself(use a loco that might not be your favorite,experiment on the guinea pig)
The trick is not to over do it. Always wipe off excess no mater how excsssive it is. Clean wheels with rubbing alcohol to remove dirt and grime(this enhances electrical pickup). Make sure you use cleaners that are non abrassive and don't leave oily residue(they pick up dust & dirt the loco enemy). Steam locos need lots of TLC. I have obtained a few units that were one toss from the scrap heap. TLC brought these back and you will be happier you did. As for wheel sets,couplers and trucks Kadee makes great stuff, but you can look for just about anything on line to see what YOU like. Cheaper rolling stock can be switched over but some times its just easier to sell it and take your bank roll and chase bigger game. The Walthers Reference Book gives you lots of ideas and companys to choose from besides going on line. I live in Wisconsin so Walthers is just 2 hours down the road from me. They have a great selection and its worth the Bang for You Buck! As you start posting on the Forum feel free to Show Off your collection and ask questions cuz the one thats not asked could really help you. Hope this helped and see you on the Forum.