Yet another newbie

Hello,
I run a webstore and currently am working only with paypal. After reviewing OSCommerce and Zen Cart, I feel ZC is the way to go. However, I do have questions (surprise, surprise). My apologies in advance if these have been asked and answered. I conducted searches but after an exhaustive search through over 100 pages, I decided to go the easy route and just ask.

1. My website is on Yahoo. Can anybody answer if they know if Yahoo supports ZC?

2. I already have a site I'm happy with. By using ZC, do I basically rebuild all my pages, or can it be integrated into my exisiting web pages?

3. I found the answer to this question I think, but I'll ask to be sure; customers can create accounts and login via passwords, correct?

4. If I upload ZC to my host directories, I can work on making it without it interfering with my existing site, correct?

5. this last one is the most confusing of all, I can handle PHP, code...whatever. What really stumps me is what I need once it's complete, meaning to get credit card payments going. Merchant Accounts, gateways, all that jazz leaves me scratching my head. I need somebody to tell me exactly what I need (and don't need) for accepting credit card payments.

I'm sure these have been answered before, but thanks in advance for any insight given.

1. My website is on Yahoo. Can anybody answer if they know if Yahoo supports ZC?Yes. Some have run Zen Cart on Yahoo hosting, but they have typically encountered some challenges in getting it running due to the way Yahoo has their servers configured. It tends to run a bit slower on their servers too, due to the broad loading of the number of customers per server they allow.

2. I already have a site I'm happy with. By using ZC, do I basically rebuild all my pages, or can it be integrated into my exisiting web pages?Zen Cart can be "skinned" to look like most site designs; as such, it's best to bring all your existing content into one place to manage: Zen Cart.

3. I found the answer to this question I think, but I'll ask to be sure; customers can create accounts and login via passwords, correct?Yes

4. If I upload ZC to my host directories, I can work on making it without it interfering with my existing site, correct?If your existing site doesn't use an "index.php" file, then you can upload it directly to your main area without likely conflict. To be safe, you might want to load it into a "/shop" or "/store" or other folder instead.

5. this last one is the most confusing of all, I can handle PHP, code...whatever. What really stumps me is what I need once it's complete, meaning to get credit card payments going. Merchant Accounts, gateways, all that jazz leaves me scratching my head. I need somebody to tell me exactly what I need (and don't need) for accepting credit card payments.
   In a very simple nutshell, what you need is:
   A. bank account
   B. merchant account, subscribed to with a merchant service, who deposits collected monies into bank account.
   C. payment gateway, subscribed to, often via the merchant service, which authorizes CC transactions using merchant ID.

Here are some recommendations:
http://www.zen-cart.com/index.php?main_page=infopages&pages_id=27

Holy Cow! What a quick reply. Thanks DrByte for the answers. Much appreciated. More to follow, I'm sure.