It depends on what you want to order from Alibaba. Alibaba is just like any other website where you can buy things online and that too at cheap price.

Normally, if you wish to order something, you just have to add that product to the cart and do the payment process etc. If you wish you may have a word with the supplier as well(contact of which is provided where the product is listed) if you have any doubts/questions.

I have ordered few items like sun glasses, watches, pens etc via alibaba. Initial 2-3 times when i ordered i didn't had to pay any duty but as we started ordering on regular basis and on the same address, we had to pay duty on some products(may be coz when you keep ordering on regular basis, it comes under customs scanner & so it attracts import duty on the products you order).

Ordering from Alibaba takes about 15-30 days to get the product delivered depending on the courier service you chose. If you are paying additional charges for shipping and getting the product by FedEx or DHL, then may be you can receive the products earlier.

I hope I have answered your ques. If you still have any ques. then plz do let me know.

Thanks.