every e-commerce project is unique. here are some steps that i would follow in setting up a new e-commerce website

1-registering domain name
2-finding good, secure hosting
3-installing e-commerce software package
4-populating database with model #, prices, descriptions
5-creating site template
6-set up payment processor
7-installing analytical reporting solution
8-advertise and promote the site

this is the best advice that i've got so far but i still need to do my homework specially in optimizing it

That's a good advice goodroi. It's not easy to set-up e-commerce site but you can do it if you have determination to do this.

Let's say;you set up an ecommerce site appropriately and eventually the site is not indexed or not providing the expected results.Then have you done a great job or not?Setting up an ecommerce website needs to take into account SEO and SEM Marketing strategies.If your site is not properly markete then it is "zero travail"Primarily,before you start with any design or setup,you need to know who your customers-to-be are and targeted age groups and as well as communities for the products you intend to sell.To get the above information,you need some good period of time to carry out a feasibility study online and offline about the products you are wanting to sell.Once you have this in place,then you can start with setting up the site as the feasibility study will also give more insight into the design needs for your customers.
This is the more reason many online business never succeed.How many ecommerce are there in the search engines and directories?How many of them are making money,profits or revenue is a question to take iinto consideration.
You will also need persuasive marketing skills materials and these includes and not limited to text on your site,your landing page(s) also need to be able to call your site users to take action.But then what do i mean by take action?It is the art of converting sales.This is what I have always been doing and I am really a happy person.Cheers

You can install free oscommerce for your ecommerce project assignment and play with it to get all the information you need to complete your homework.

You need maybe to use Magento, It's a very good shopping cart

I don't advise you at all to get oscommerce it's a pretty old system which has never been renewed for the actual Internet design layout.

I already used this system and the admin backend does not allow you to place severals photos for your product.

i also tried magento and it's a best option if you can't do an ecommerce site on your own

Which is your opinion about 8 - advertising and promoting the site: Best route of action?