Is it safe to send money via western union to a business that is oversees?

i was hired by an arts and crafts business in the UK to be an accountant for their company. i have never met these people nor have i spoken or seen them. my job is receive payments on their behalf from their customers in the US, deduct my weekly pay of 10% from the payment sent to me (by check), and then send the remaining balance through western union. this is my first time doing this. is there something i should be aware of? is this a scam? i just got a money order and now i think i should send it, because its not my money. i was advised to send it to Nigeria. is that a good idea.... someone please help me out! thank you SOOO much!! =]