Where can I get a legal advice for digital contents ?

I think that the only certain way of getting the info you need to hire a lawyer. Any advice from other sources is advice of which you will be uncertain - how would you know if the person giving the advice knows what what they are talking about?

You would need to check that the lawyer you deal with is knowledgeable in this area.
I would suggest you check with law firms, and ensure that anyone you see specialises in this type of work.
Check online to see if there are any negative comments for this firm.

You could also consider insurance against being sued giving you financial protection any claims which could be made against you - a lawyer could advise here ( 'though such insurance could be expensive) and may be "over the top".

You are right to want to get appropriate information in this issue.

A good piece of advice is to simply be careful of what you publish online - use your own due diligence. Take care using trade marks, peoples or companies names etc.

Thanks Greg, I am trying to use mine, but as far as web designing, you can't guarantee the source of photos when you outsource a project.

I like the idea of insurance against being sued. As far as getting a lawyer, I am wondering is consulting a firm is the right move ? Is there anyone dealt with such a firm and know a good one that I can contact ?

I never hired a lawyer in my life, so I have no type of any knowledge. This is why I am wondering how websites are doing that ? do they hire lawyers or is there type of companies who do these stuff ?

You would want to talk to a business lawyer on the phone. That time should be free. Then ask them if they have any experience in online business. They either will or won't, and if not, then ask them for a referral. They should be able to find you someone that specializes in that area of the law.

I have a monthly service for legal advice. They have a plan where you can put your business on the program. That way you can call as often as you want for advice. They will prepare or review legal documents for you at no charge, other than your monthly premium. If you need them to work on a case, you get a discount from the regular fee. Some things are covered up to a certain number of hours, then the discount kicks in. It is pretty cheap, and well worth it in my mind.

If I was in your situation, I would call and ask them my question. They would assign me to a lawyer with that expertise. If they didn't have one, they would refer me out to another lawyer and the same rules would apply. Free online consultation, and then the work is discounted 25%.

But anyway, in your situation, I would contact a business lawyer locally, and then start the questions and get referred if they didn't have the needed background.