Promoting a website contains 2 main options- promoting it for free, or buying advertising spaces.
First , I would suggest to examine websites which have the same idea as yours. Follow their promotion methods, for example check which websites are linking to them by typing their site addresses on google, or if they use any affiliate program to boost their sales.
The free way- Try to find potential websites that can link to your site. That would be a hard task, depends on the site subject. As for your website in particular I would recommend posting your products on free social shopping sites, like the following:
This next
Kaboodle
Other than that- adding your website address on your signature to every message you send, and to your profiles on different websites.
Paid advertisments: you can run campaigns on different networks. There is a large variety of networks, but finding the ones that would return your investments can be tough. Here are a few links for paid advertising companies:
Google adwords
Adbrite
Fast click
Affiliate program: You can start letting other sites promoting your products, and pay them only for qualified sales. This is a great promotion method, but the trick is to find affiliates. You can use a third party company to manage your affiliate program and to introduce your goods and website upon potential affiliates. Sample website for that is commision junction .
Keep in mind that keep visitors coming to your site and reffer other visitors is no less important, but thats belong to another question ;)