Personally I use BlueHost for both of these purposes, for $6.95 a month my hosting and domain registration fees are paid for. It comes with a privacy package so that harvesters cannot find my name, address, etc. via a whois lookup. It is widely considered to be the best webhosting company currently which is a title they have earned, the customer service is amazing and I experience 99.8% uptime. I am allowed unlimited domains so all of my sales pages for products, separate websites, etc. are all hosted on a single account as I have enough storage space for about 2400 different websites (based on average size of my sites) and 15TB of data transfer a month, which I estimate to be enough for around 4 million visitors monthly. Your first domain is also free if you buy a year or more in advance, which I would recommend as you save a ton of money upfront (any one of my sites makes more yearly than my hosting fees this way). To find the right domain name use their domain checking feature to see if it is available. To sign up, click here.
Creating your websiteCreating your first website is a great experience, odds are it won't look very pretty but as long as it gets the job done you are in the right direction. I prefer to use templates for my sites as it decreases my work load immensely. I usually grab one of the cheaper templates ($30-50 range) from TemplateMonster. I then edit the template in DreamWeaver or notepad to include my links, content, etc. This is where I stick in my affiliate links as well, I'll get to that a little later on.
SEOThis is a topic that I could literally write a 300 page guide on without getting out all of my ideas. SEO stands for search engine optimization, this is the most essential part of running a website designed for affiliate marketing. It determines how you rank in search engines such as Google for various keywords. The basic premise of SEO is that you need lots of links that lead to your website (and they need to be from reliable sources). Many times I will simply pay others to do it for me because I will still turn a profit and it decreases the amount of time I have to spend on it (besides they specialize in it). I always use LazyURL for my SEO purposes, I typically buy a 1500 pack of manual directory submissions and 150 social bookmarks and I'm set with my website. I will write and promote a few articles, more on that later. Afterwards I just sit back and watch it crank out income for years.