Short answer: Because this is not yet a thesis or scientific publication, you may be able to cite websites instead of papers and books (your Q1 question). Other answers have already discussed the format of citing a webpage (Q2), and there are a few related questions on academia.stackexchange.com.
However, there is also the long answer:
You should try very, very hard not to cite websites. The reason is that you should not use websites as sources for scientific information:
- The website may disappear after publication, making the reference useless and putting the burden of trying to find an archived version on the reader of the work.
- The website may change (and become irrelevant or wrong).
- Websites are (more often than not) full of mistakes.
- It is hard to verify the reliability of the information if you do not know where the author of the website got it.
- If you do know where the author got the information, that is probably the source you want to read and cite (see also: wikipedia on Chinese whispers).
So the question is: why are you using the website(s)?
To learn something that is "common knowledge"?
If you use a website to learn something that is common knowledge, there is no need to cite it. The exception is when you copy text literally from the website, but that is usually frowned upon and sometimes violates copyright (even if a reference is added). In most cases you are better off by reading multiple sources and rephrasing the knowledge to fit the style and application of your work.
To learn something new?
If a website describes something that is not common knowledge, you should ask yourself where this knowledge came from. That will often lead you to a better source to cite. This is a check you should be doing anyway (even when reading and citing scientific papers) to make sure you are citing something that is scientifically sound.
Because you found the one website on the internet where good scientific research is published that is not published elsewhere?
In my field (biophysics) I have never seen any examples in grant proposals, scientific papers, or other academic works where a website contained useful information that was not available elsewhere. But if you found the rare case where citing a website is really necessary, you should absolutely do so. By citing the website, the interested reader knows where to find more information (hopefully, this was discussed above). And of course you would not want to be accused of plagiarism.
Because of a lack of time?
Totally understandable, but not exactly a good reason.