Deepbit is the best site there is and definitely when you are new. Deepbit is the only site that is easy enough to start with.
They explain what you need to do and a lot of youtube video's about setting up mining are using deepbit to register.
Thats may be true, but its just newbie-friendly, that doesnt mean its the best. Its good for being introduced maybe, but in like 1 week or 2 your ready to go and explore other better pools