The first thing I get asked is where to host and register domains. I just switched to Hover.com for my domains and DreamHost for my hosting. I use Google Apps for my email so that I can have my own domain instead of the @gmail.com domain. I have not had a chance to do an install of Word Press or other apps, but that is key in finding any provider. One click installs where you choose an application and it is installed for you is the best time saver. I would stay away from hosting and domain companies that bombard you with ads trying to sell you products and up-sale your current ones (*ahem*, like my previous provider).
You can choose to have one company host your domain and site, or keep them separate. I prefer separate companies because when it comes to the day I feel I need to switch it makes it easier if they are not tightly integrated with each other. I can transfer the domains one week and then hosting provider another week or vice versa.