Using ads inside startup pages to pay for expenses? And what advertisement solutions work best?

Has anyone added banner ads to there startups to monetize from the beginning?
Is this a good idea or better build a memberbase first without any ads that may turn people off? I will be have a free plan and a payed plan.
Since im mostly improving product quality and not be adding "premium" features at this point I want to offer the ability to upgrade to remove the ads and some small + features, then increase the price each month as more premium features are beeing included, or existing features moved into the "pro" plan.

2 questions:

1. Any thoughts ideas on this?
2. What are good company's to work with to monetize your website ( google? others? )

The Revenue Model, is a very vital part of your product (unless, of course your product is a fun-oriented Instagram-kinda one). There are several popular models that you could pick from, such as Ads, Freemium etc. But how you pick is not a casual decision.

If you pick a model where customers pay for your product/service, Pricing comes into the picture. There is ample advice to be found on the Internet on the same.

If you resort to Ads, remember that it's something that's been over-utilized over time, and people have grown to hate them unless you do it right. You could also check out Retargeting.

Bottom-line: To arrive at an answer to your question, you should sit down and get deep into what your product is/does. Though you can take help, it's ultimately you who should decide. Afterall, you're the one who knows your product best. In the world.