Like /u/kreamy said, use Khan Academy as a supplement. Don't rely on it too much. I haven't used it for calc 1, but I did check it out for later clac 3. It's something I would look at pre-lecture or for a quick concept check, not as a substitute for lecture or text. Other resources I would recommend is Paul's Online Math Notes and PatrickJMT. The latter is awesome, he goes over many frequently asked problems in calc, highly recommended!

In terms of text. I used this: http://stewartcalculus.com/ (Early Transcendentals) and the this: http://larsoncalculus.com/

The text by Larson is much easier to follow, so you could use it as a supplement. If you want the "best", check out Calculus by Michael Spivak.

Since you are doing it online: YouTube playlist of MIT calc 1 lectures

If you have anyone questions feel free to ask. Stay motivated and have fun.

www.khanacademy.org will have lots of information related to Calc 1. Use it to supplement your course material, or to review before a test. That's what I did. Other than that, if you've made it this far in your education you should be fine. Just keep up with the material and do your homework!

I took Calc 1 over a summer, online in 10 weeks. I think I'm qualified from experience to give a little advice (I also did Calc II in person in 8 weeks.) :)

1. If you have a couple weeks before the semester starts, I would recommend brushing up on pre-calculus and advanced algebraic concepts. I say this from a grade saving standpoint; the first test in most calc I classes is review... you want to ace that.

2. Don't. Fall. Behind. Leave ample time to get stuck and to get help; if your instructor does not have in-person office hours then you definitely want to leave time for an email train.

3. For it being online, it mostly depends on the format your instructor is providing. We had WebAssign type problems, which is a standard, so since you may have that I would suggest definitely watching the videos that accompany problems if you're allowed to. They are super helpful.

4. Ultimately, being in an online calculus class will feel like you are self-teaching. Because of this, it is important to find supplements that are specific in concept so that if you are a little confused on a certain topic you can go straight to it in your supplement and get an outside perspective from whatever your instructor is providing. Lots of the supplements listed by other Snapzites are ones that I would have suggested such as Khan Academy.

Resources I found useful:

http://www.wolframalpha.com/ can be helpful in your learning development if USED RESPONSIBLY. If you depend on it for answers, which often you can get, you will hurt yourself. If you use it to clear up confusion or advance information on certain topics and problems, it will help you.

The next one I hesitate in suggesting because it has the potential to diminish your learning experience, but you would easily find it via a Google search for calculus help, so I might as well mention it because I found it extremely useful...

Problem solver - https://www.symbolab.com/ this is a site that will solve calculus problems for you and show you solutions step-by-step. Once again, this only helps you if you use it responsibly. If you use it to get yourself the answer without understanding it, it will hurt you. Wolfram Alpha has a similar tablet app called Wolfram Calculus Course Assistant(?), it costs money and does the same thing as symbolab, but it does have alternative approaches to problems sometimes so maybe it is worth it to you.