They will send you the Money Orders or checks and ask you to deposit them into your bank account and then wire the money to them via Western Union.
Usually they say to keep some money for your trouble.
usually involves this scheme: the scammers upload fake attractive photos, in most cases of white people.
They pretend to be the foreign specialists working in Nigeria or Ghana (usually originally from US and UK, but it may also be Canada, Australia or any other European country).
Nigerian scam comes in many forms: 419 scam, when they offer to transfer millions of dollars into your bank account, or lottery scam, when they tell you that you've won something in some bogus lottery.
However, Nigerian dating scam (or romance scam), besides just asking for money for their studies, sick relatives, etc..
There is also a re-shipping scam, when they will ask you to re-ship goods for them.
These goods are purchased with stolen credit cards.
Needless to say, those Money Orders or checks are no good, and not even worth the paper they're printed on.
If you cash them or deposit them into your account, Money Orders or checks will come back after few weeks as fraudulent and you will be responsible for paying back the money to the bank and sometimes even charged for passing counterfeit instrument.
Never re-ship anything for strangers, especially to Africa.