I have a page on my site that is quite long and I plan to put in some links at the top which will scroll the user down to the relevant section. If I do this, will these extra links to the same page help or hinder my SEO efforts? What else should I do if this isn't a good idea?
People will say alot about anchor links. In my opinion other than increasing your keyword density for that page, they won't directly benefit your SEO efforts. It is my opinion that if you need them to improve your user experience, then you should feel free to add them. But they are a hyperlink so, don't fill your page with 1000. Keep it limited to what you need and you'll be fine.
Thanks guys, I really want my site to work for my users, but it's also important to be listed in the search results so your answers really help.
Either way, it certainly won't hinder your results. If you look at it from Google's point of view: the fact that you have anchor text with your keywords should be telling Google that your page is relevant for those keywords. As a little known grocery store once said... "Every little helps!"
From my experiance on this yes they do have extra impact, of course doing it will raise your keyword density, but if its a link then extra value is added to this occurance of the keyword. Same as the word gets a bonus if its header text.
Onpage anchors work magic as long as you have a lot of PR to spread around to your other pages, I highly suggest optimizing your site for it.
There is no SEO benefit from links that point to other parts of the same page! If there were, it would be a very easy way for spammers to get top rankings. They do help in the usability of lengthy pages, though.
That's an interesting suggestion, but why would you nofollow if this isn't going to an external url? Is this just to prevent the SEs from adding a penalty for keyword stuffing?