Meta tags will soon be depreciated. With google not taking any notice of them at all, the competitors will catch on, probably already have. This is what google have to say. The search engines which use meta tags, i see as having the worst and most irrelevant results. It's all about page content, and your <title> tags. Myself, I’ve never used meta tags - On a blog it could be a bad idea too. If your going to get penalised for meta tags not matching your content, then as a blog has dynamic content (which it will have) then your going to lose valuable keyword positioning.
That's not true. There are different META tags. Probably Google doesn't consider the meta="keywords", but other META are very important. Please search whatever phrase you want with Google, and probably you'll see the content on META="descripcion" on many results
It MAY appear that google uses meta tags, however, it does not. Well, if there is no significant content on a page. A lot of the time people use "keyword generators" to make the keywords for the description tags. These generators usually strip down all the HTML and check the page for keywords only. It does the exact same process as google, therefore you are presented with exactly the same results. It may appear google does. http://www.google.co.uk/search?hl=en&q=does+google+use+meta+tags&btnG=Google+Search&meta=
You're asking the wrong question. Why would anyone ever want to find and read your blog? Because your blog SAYS something they're interested in reading. The keywords should reflect your CONTENT. So what IS your blog about? Example, if it's a blog about dogs, and more specifically about people owning dogs, training dogs, having funny incidents with dogs, tips and tricks, food and health, whatever, then your keyw ords would reflect that. Example <meta name="keywords" content="dog, hound, canine, dog owners, dog training, dog food, canine health, dog stories" /> Notice I didn't say "dog, dogs, doggs, hound, hounds, canine, canines, owners, training, food, health, stories". Your blog is not about people who own things, general food, general health, writers or novels, AND search engines like google will usually include words which container the search terms like "dogs" will come up when you search "dog" and "dog" will come up when you search "dogs" and will usually also try to correct spelling. If you have great content people want to read, you won't need any keywords. Google used to use them as part of their algorithm, but now I'm pretty sure they still look at them but their influence on the overall score is almost nil. They're more likely to have an impact on any other search engines when they match the content.
from my experienced meta tags is one of the most important thing on a website if you want to receive traffic from google or other search engines.
using meta tags is a good practise, but number of keywords shouldn't be more than 9. try unique keywords and no repetitive words.