I'm planning to be ready to start querying in about 6 months and I was wondering if there was anything beside the submission that I could do to help myself. Should I have a website? If so what do I put on it? A blog? Do I need to start using Twitter or Facebook?
An agent isn't likely to look at a blog or social media unless you mention it. And you're going to have to ask yourself if that stuff is worth mentioning. Will your website include links to past publications? Are they good publications that will help you here? Is your blog going to be somewhat related to the work you are sending out to agents? Six months isn't a lot of time for a blog to gain any real traction. Is the writing on your blog going to be as good as the book you are querying? I believe sometimes these things can hurt a writer more than help them. I don't use social media anymore, and I don't have a website. I will say that I did have an agent contact me on twitter. He had read a short story of mine that the magazine linked on twitter and tagged me in it. The agent wanted to know if I had a novel he could look at, and luckily for me he said that there was no expiration date on this invitation. But here's the thing. Me actually being on social media had very little to do with it. It was more the magazine being on social media that resulted in this positive outcome. If I had just posted a link on my own twitter or Facebook or whatever page, I don't think this agent would have come across my story. And without being on social media, it's just as easy for the agent to send a note to the publication about getting in touch with me. Agents are busy people. What's going to count more is your query letter and then your actual pages. You want to agent to read what you are submitting and hoping to publish. Personally, I wouldn't want to distract them with reading other things outside the scope of your novel. Definitely list prior publications (if you have a few that are worth listing because some are better to leave out). But you don't want to include links to that sort of thing in your query. I would keep the focus on your novel. It all comes down to the novel.
While @deadrats has some good points, he is dealing with the short story market and not novels. I detest social media, but it can be useful in building a fan base for longer works. With Trad pub, the publisher may have an authors section on their site. For self publishing a personal website, could assist with building your fan base, but social media might be a better option.
I know I write and publish short stories, but I was talking about getting an agent you want to sell your novel, which I believe is what the OP is asking about. And, just FYI, I also write novels, though, I am yet to publish a novel. Still, I believe my insight has some value here.
I didn't say you didn't have insight. Based on your previous comments on the board, i took your comment to be based on the experience of a short format author. That is not to say the perspective is not valid, simply that it is different.
My comment was about querying agents about a novel. It doesn't really matter if I write short stories or not. I understand we are talking about getting an agent for a novel, which my first post here clearly addressed. My comment is not coming from a short story perspective. I know a lot about how the publishing industry works, not just from the perspective of a short story writer. I think my advice is still solid here. And it feels a little like you are trying to discredit it somehow for some reason.
Ah, well I'm going add my own angle by speaking from no experience at all. Here I go: The modern cynical take (which I'm inclined to agree with) is that trad publishers expect you to do a lot of your own marketing. Having an online gravity (number of readers of other works, or followers) certainly wouldn't hurt your chances. Though... that time and effort is probably always better spent on writing a few damn good books and queries. Further I think it's smart to honestly ask yourself if it's worthwhile pitching your very first novel (assuming this is your first). Maybe you knocked it out of the park on your first go like King, but the law of averages indicates you might not have written Carrie yet. Carrie might be your second or third book, and from what I've seen, querying is a lot of work. Well, so is self-publishing. Either way, best feet forward is time spent best and all that.