If I want to design a WordPress site on my domain and then transfer it to my clients domain, once I’m finished designing it, would it just be a matter of transferring the documents or would I have to change settings in WP?
well – you would normally design the template and transfer it. The template itself holds no dynamic information, so implementing it onto your clients site would be like changing the a template on WP. The only things you need to think about is if you have changed the front page to be static or assigned certain pages to a template. That can be quickly fixed though once you have the site up on your clients domain.
If you set up your clients tempate and content all on your test site, then move the template across expecting the content to move, then it wont, you would have to copy the database over as well… which is always fun ;)
If they have wordpress running already, you could try and connect a wordpress install to their current database… although I have never done this with wordpress it might work, giving you all the content to style and all the pages to implement… then when the template is finished you can just upload it and activiate it on your clients site.