Often times a "bunch" of old trains will include rusty or "oxidized" track. It is seldom of any value and may be better discarded with one exception and that is switches which can be worth cleaning up by a collector. In all cases NEVER use steel wool to try to clean these rusty or oxidized items. Also many smaller train sets came with small transformers which are seldom worth the cost to ship them anywhere. Otherwise, the most value will be in the engines of the set followed by any accessories and then the cars themselves.
Do not discard any of the boxes or instructions that came with the trains. These are desired by collectors as well. Most of the engines and cars are identified by a number on the side of the car or engine which a collector can use to identify what you have. Pictures are most always needed to start to arrive at identifying and setting a value for the trains and a collector will most always request these.
Lastly, do not attempt to clean your trains with any abrasive, steel wool, or cleansing agent of any kind. Many of these will do more damage than good. A true collector will know what should be used and preserve the value of the trains.
Lionel has been making trains since 1900 and has a well deserved reputation for quality products. Many of the trains made in the early years right up through the present have kept their value and some are highly valued by collectors, while other more common ones, while worthy of running may not have a high collector value. The value of a particular set or piece is dependent on several factors such as condition, rarity, and the presence of the original box in good condition. Several companies have published price guides which list a value for most of Lionel's production. Two companies that publish respected guides include Kalmbach - www.kalmbach.com and TM Books and Videos - www.tmbv.com. Keep in mind that values listed in these guides are just that - a guide. Often when selling trains, they must by offered at a price below the listed value to sell quickly.
Members of the LCCA can list trains for sale and purchase trains from other members in The Interchange Track. This magazine is issued four times a year and there is no charge to members to list items. In addition to the magazine, members also have access to an online listing service, eTrack - again at no charge. These listings also serves as a guide to exactly what items are selling for. Items are conveniently listed in numerical order, making it easy to find a particular item.