If you are waiting for the sale to happen doesnt mean that you cannot earn from your domain name. Infact there are many domaineers that earn much more from traffic on a regular basis. So how to you monetize your domain names to make money.
1. Choose a parking provider which offer's free content, such that you can develop several domains in a day. So if you have 100 domains, chances are that one of them would get traffic and you would earn from advertising. Check
2. Develop your domain on your own and use Google adsense or some similar CPC network.
3. Simply use one of the parking providers
- this option will not be as good as option 1 since the standard pages provided by any of these parking providers are not inviting and most web surfers know from the design that its a parked domain. However this option is good if you just want to park 100s of domain or if your parking provider provides you with some great landing pages which would result in clicks and income.