320 links is a good start, definitely better than 0. Make sure your links are relevant to your niche, as well as high in Page rank ( at least a PR 3 ).
go on Google.com and search for: site:www.mydomain.com appears the number of pages that link to you. but only a part of it!!!
Don't stop, continue building your links up. Start building your backlinks with keywords for search engine ranks and then going from there.
It's good if your website is new but if you domain age is maximum and links are 320 so it's not good.
it really depends on your niche and what you are targeting... 320 sounds decent unless its for something like watches...
The quantity is one thing and the quality is another. And u should also take your niche, your site age and numerous other factors into consideration before u could make a judgement of your site's performance.
bascially, I could recommend you to have a research of your competitors' performance which could tell u a lot. At least, the contrast and comparsion are the most direct indicator.