Hi Debra, general rules are
If they ask you for money at anytime, and especially by Western Union or Moneygram, they are a scammer
If they fill your email up with long screeds of romantic cut and pasted protestations of love, happiness and eternal bliss, they are a scammer
If they say they are American/English, and an engineer, who just happens to be working in Nigeria/Ghana/other African countries, they are a scammer
If they say they are divorced/widowed with one lovely child, sometimes 2, and declare they love you and want you to be the mother to their children in 2 weeks or less, they are a scammer
If they ask you cash their paycheque due to the bank in Nigeria/Ghana etc won't, they are a scammer
Remember that a lot of romance scammers are very good at what they do, they can string someone along for several months and not do any of the above, then suddenly ask for money.
But basically, check the email headers, if they come from Africa, they will be a scammer
If you are unsure of how to find and read the headers, read here
http://www.spamcop.net/fom-serve/cache/19.html , and here
http://www.emailaddressmanager.com/tips/header.htmlThen copy paste into here
http://www.iptrackeronline.com/header.phpThis will tell you where the person is in most cases, some email servers strip the senders address though, so you are left with the list I posted above of guidelines.
Take care
John