With the website being edited by many people it can become untidy and unattractive unless an effort is made to use some consistent styling. You can write your own guidelines but here are some suggestions for starters. While I have written them in a directorial way I don't mind if they are changed so long as the appearance of the site is updated to maintain coherence.
Try to make titles short and meaningful. Capitalise principal words as you would for a book title. When adding a menu item, the title is often proposed as being the same as the title. If anything, the menu link may want to be even shorter but may take meaning from its place in the hierarchy. Because the main menu is styled in all capitals, only give the first word of a menu item a capital.
Structuring your page
Use the heading styles h2 and h3 from the dropdown list of paragraph styles to structure your pages. Use h2 for a major section and h3 for subsections within it. Do not create additional heading styles of your own devising using bold, italics or capitals because the site will become a mess of different styles. More heading styles can be added if you really need them but consider splitting a page up into several smaller pages instead.
Apart from tidiness, using headings correctly helps search engines and permits instantaneous site wide changes to the style of the headings such as changing font or colour.
Links stand out in a page. If you link meaningful words then a page can be scanned quickly and you can easily find a relevant link. Avoid "cliick here" links at all costs! Firstly everyone knows how to navigate links so the word "click" is irrelevant and even wrong for people who don't use a mouse. Secondly having the work "here" jump out of the page in half a dozen places does not help with that quick scan. Thirdly, it interrupts the flow of reading. Just write normally and then link the pertinent words in the sentence.
Always supply alt text for images. This is the alternate text that a screen reader will say to a blind person viewing the image.
Tables exist for presenting tabular data such as experimental results. They should not be misused for presentational purposes as this will confuse machine readers such as used by blind people.