Most collectors equate the "illustrated news magazine" (news publications illustrated with engravings, published in the last half of the 19th century) with Harper's Weekly, begun in 1857 or the rarer Leslies Illustrated Weekly which started in 1855. Prior to this there were a few others such as Gleason's, and Illustrated News (founded in 1853 by none other than P.T. Barnum). The first one, though, started in the boom town of San Francisco on September 1, 1850, The Illustrated California News. It lasted a mere six issues and contains unique and important images of early California life. There are two complete sets of these known to exist. I am fortunate to own own one individual issue, which I bought some years back from my friend Richard West of Periodyssey. This was the only copy he had ever handled and Richard sees more rare American magazines than anyone. When I heard of the the existence of a complete set of these in late 2007 I ponied up more than I had ever spent on a magazine purchase before, $15,000. Though times are a little harder at present, I'm still quite happy I took the plunge. It's too early to speculate whether or not the economy is affecting prices of these collectables and but I think it's safe to say these wont drop in price to the same degree as the stock market.
I guess this is a pretty good segue into an important collecting philosophy. If you buy the best and rarest you will rarely go wrong (look at the price of the famous one cent British Guiana stamp or the Honus Wagner T206 card, for example). The problem with many unsophisticated collectors is that they begin by hoarding everything in sight and before too long are inundated with mountains of inexpensive material that they eventually wish they hadn't bought in the first place that rarely is worth as much as they paid for it. Every collector will tell you regretful stories of "the one that got away".
Principle number two. Collect because you enjoy it. Never buy things with resale in mind. Good and truly rare items will always appreciate. When a dealer tells you a piece is "a good investment" run in the other direction. Caveat emptor!
Three. Do your homework. In collecting, knowledge is power. Scour any reference you can find in your chosen field. Dealers often know less about what they are selling than an astute collector. An EBay addict as I am, a day doesn't go by that I don't see some item that is either misrepresented or underdescribed.
Now go out and have some fun. Isn't that what collecting is all about? Thanks for reading!