I had an adsense account. Please give me advice when I can put adsense into my website is best (my website have about 10 visitor / day)
You can put it onto your website now, but you'll not make much (if any) income with 10 visitors a day. You need to concentrate on building up your traffic.
I recommend straight away because you can always make a few cents which is better than nothing. Later on like a few months you'll notice a small change in income.
At 10 visitors a day, I would focus on increasing my traffic to at least a few hundreds a day before putting adsense. I mean you can put it right now, but what for? Focus on increasing your traffic and when you get there, you put adsense and enjoy seeing correct numbers immediatly, no need now.
I think once you start finding out who your readers are and getting a lot of traffic. I would say around 500 hits a day and it's time to monetize. personally I started with ads right away and so can you.
I wiill recommend you to wait a while. Get some quality backlinks and some better rankings at the SERPs. It is easier to get links to a site without Ads.
You can apply for adsense within 7 days of starting your blog. Just put some unique and quality articles and apply for adsense. If Google thinks that your site is eligible for getting an ad then they'll approve your site for adsense.
I think need to some time to increasing traffic, after some time later getting good traffic than using Adsense. Days is not a issue....
Visitors or not at all matter to adsense account. More visitors more money to you that's all. But at-least monthly 2 adsense clicks required.
You should put the Adsense code as soon as possible. Its not a good idea to leave the money on the table.