You deserve it. This is a huge milestone, and one that needs lots of marking, with jumping, screaming, dancing, and general merrymaking. Whatever your preference of celebration. Just enjoy yourself and your accomplishment, and also be sure to gloat to everyone, because that makes you feel even better.
Don't look at, think about, or even dream about your novel. Leave it alone. You need to get some space after all the hard work you've done. This will help you (A LOT) when you get around to editing, and just in general with your mental health and all. You can't celebrate forever, my friend, however much you may want to. Go do other things and be successful. When you've done this for at least a month, preferably more, you can move on to the next step.
All right, I know this is almost no one's favorite thing, but if you're planning on doing anything with that dear novel of yours, this is completely necessary. Trust me. There is NO GETTING AROUND IT. I tried to ignore it and failed. You must edit. Even J.K. Rowling edits. Even Stephen King edits. Whoever it is you idolize, they edit. A lot. So must you. So dig your heels in and get to work. I've got tips on this elsewhere, go ahead and look around. Recommended Posts, up on the menu bar, has links to all the basics for you!
I put this after editing because, for your sake, you should edit at least once before having anyone read your work. Of course you have to do more editing afterwards, like, a lot. That's the point of beta readers in the first place.
So if you're feeling brave enough, or are willing to push your comfort zone a little, this is the point at which you start thinking about people you can have read your book. Beta readers aren't generally writers themselves, just friends and such, but if you feel more comfortable with writers, go that way. You can also get critiques online at first instead of in person, if that's safer for you. The point of this is to get outside eyes and outside advice, which is absolutely necessary for doing important publish-y things with your novel.
Get them beta readers, and then move forward with your editing and your lovely life.
Thoughts? Extra advice? What is the plural of "series?" Seriously, someone please tell me.
Images via wristwatchreview.com, tjohnsonmediagroup.com, and manicreaders.com.