I vouch for Aliexpress. They're pretty much the same as TaoBao except they actually ship to the US and have a good customer service. If a product doesn't show up or there's issues with an order, I've always had a refund or replacement. There are reviews on the products and customers sometimes post pictures which really helps. I am petite, so sizing is never an issue for me personally but, if you find asian sizes run small, its best to size up.
Shipping varies. The free shipping on ali takes like 1-2 months. If lucky, 3 weeks. I think Ali has express shipping but you'll have to pay like $10-$30 for it and it kind of defeats the purpose of saving money on cheap things.
I've only bought clothes or accessories. But so far I;ve liked what I got. just read the reviews and you'll be fine