To be more accurate, to answer your question. Sandbox is only when a website is abusing googles algorithm and spamming, this can be a white screen, when entering your website url and not showing up anything.. I would advise to use googles webmasters tool and submit your site, and having a site map helps as well.
Google can pick up your site minimum of 2 weeks or more. This would mean, where ever you are guest posting, is this persons site page rank high? If your promoting hard, and not seeing any results, it may because you overlooked your competition.
Why do I say 2 weeks or more? The most crawled websites are ones that are index with google for a long time, and getting constantly updated with new content, etc. Think more of quality, then quantity.
Important Tip: When you are linking or guest posting, I hope you are using your keywords to add more weight with google.