For me period maps are the most difficult to find. For BLOOD MOON OVER BRITAIN, a thriller set in Britain's darkest hour during WWII, I used tourist maps of London and kept to the places I knew best. From previous tours of London I already knew what areas were hardest hit by bombs and the oldest tube routes. Also I got a German bombing map of London from Deb Lawson. Her research page is awesome http://home.insightbb.com/~d.lawson/
For BLOOD MOON OVER BERLIN, a thriller set inside the Third Reich in the fall of 1939, a retired U.S. Army colonel friend of my husband sent me a map of post-war divided Berlin. He was stationed there in the '50 and '60s. Invaluable!
Whenever I can't find what I need I go to my local reference librarian. Research is his/her job.To find when an item was invented I usually google it and do some research.Just because something was invented in a certain year doesn't mean it was in common use.This is a history of inventions list. Sometimes it is mentioned when the first use occurred. http://inventors.about.com/library/bl/bl12.htm
To find out about early use of radios as communication for BLOOD MOON OVER BENGAL, a jazz-age thriller set in British occupied India in 1932, I spoke to a military historian at my local army installation. For a little background on trains in the '40's I spoke to my father-in-law who worked for the railroad for 30 years.It's helpful to speak to antique dealers - if they don't know what you need they can probably put you in touch with someone who can help you.
I interview WWII survivors and listen to my elderly relatives. Finding someone who lived in the town I'm planning for my setting is wonderful. They may give me an idea of the lay out - and maybe they have an old map.I'm member and moderator at http://groups.yahoo.com/group/WWIIresearch/
Our files and links sections are extensive. For BLOOD MOON OVER BERLIN, a fellow member helped me with research as she was a child in Berlin in wartime. Research would have taken so much longer without her help.
Old movies are founts of information.
Here a couple of undergarment sites. My favorite fashion book 20TH CENTURY FASHION,The Complete Source Book, is handy for clothing.
http://www.bobbydene.com/undergar.htm http://home.att.net/~design-house/1930s_wait_list2.htm
This site details foods that made their debuts, recipes and foods eaten in the 1930s. Also general prices for the day.
http://www.coopfoodstore.com/news/Archives/arch_pantry/oct01.htmlFor meals, I speak to my mom, her contemporaries, or take a drive to a near-by antique/collectables store to buy or flip through a period cookbook.
These sites are handy:http://www.foodtimeline.org/http://www.cocktailrecipeguide.com/I use this site:http://www.eyewitnesstohistory.com/20frm.htm
