For new sites, the best methods to get hundreds of backlinks are to submit to about 300-500 directories and do article marketing. You can submit your article to about 100-500 article sites. If you submit about 20 such articles, you can get 2000-5000 links plus 500-1000 links from directory submission. This is a great way to start off. Later on you can do social bookmarking, blog commenting, forum posting and keep doing article marketing to further increase links. All the best!
If your are going to buy paid links. Just take of few things- 1. Industry nature should be same 2. More PR site would be more benefecial 3. The page you are getting link should have minimum outgoing links
Submitting hundreds of links a day to directories is quite not a better thing. Search engines takes these as spams. Although some SEO people recommends to place 2-3 links per day.The more will your links on other website, more will be your link popularity.The process of getting links on other websites.
I think that only 2-3 links per day is playing it a little too safe. Remember that not every site that you submit a link to is going to be crawled that day. I don't see anything wrong with going out and getting 100-200 links in a day, if you can manage it. It may take spiders weeks to crawl the sites you submit to, so there's really no limit in my opinion as to how many links you can gather in that time.
Submit it to numerous web link, article and other directories. Try the best to put key phrases into incoming link text.