
Welcome to Stamp Collecting Forum!
As to your question about a collection of Fleetwood First Day Covers, you should be aware that Fleetwood (along with Artcraft and Artmaster) were three of the most prolific creators of cacheted first day covers.
As it relates to Fleetwood brand specifically, they first produced cacheted covers in 1941 and although they were recently bought out by the Mystic Stamp Company, apparently they still produce some cacheted covers today:
http://www.mysticstamp.com/faq.asp?id=76In general, cacheted first day covers from Fleetwood do not command any premium value. Most cover collectors will tell you that while the catalog value of most of the common first day covers from the 1950's on forward are valued at $1 or so, resale prices are generally 10% to 20% of that figure, so for most covers you'd be lucky to get 10 to 20 cents apiece for them and many don't bother to collect them much anymore because that doesn't even cover the face value of the postage. Furthermore, since they were mass produced in such large quantities, the supply far exceeds the demand.
Of course, if you have some earlier edition first day covers, including those from the 1940's or earlier, they can be quite collectible, as that was well before they were produced in such vast quantities that their values diminished.
On the other hand, first day covers can provide a great deal of collecting enjoyment, and many choose to keep collections such as this, especially for those who might have acquired them through a relative or friend.
If you really want to identify a specific value for each cover, you can check in your Public Library to see if they have a Scott US Stamp Catalog where values of these items may be listed, or if you prefer, ou can purchase a copy of the Postal Service Guide to US Stamps (available at many post offices for about $20). Just understand that the prices quoted are "retail values" assuming that a stamp dealer has to cover his overhead to carry the items in his stock. As stated earlier, resales by collector to collector often carry a value of 10% or 20% of catalog prices at best.