When do we need a lawyer?

Aside from corporate and transactional issues, it is prudent to consult an attorney to evaluate and secure IP assets. Indeed, a tech startup relegating 5% of its budget to legal matters is not unheard-of.

In my experience, the situations which tend to "blow up" most often involve branding (mis)decisions and failing to properly memorialize and define working relationships among founders and those employees/contractors the company engages.

Most legal efforts are prophylactic in nature. You have waited far too long to speak with an attorney if you only do so when it's time to litigate.

I generally agree with the posted answer, and would add the following: I've worked with a few start-ups, and the most obvious issues you'd be well advised consulting with an attorney is the creation of your basic building block of commercial agreements/forms/ the privacy policy and the terms of service and certainly on the HR/employment issues so that these don't blow up in your face. In addition, depending on the space you're in (let's say - consumer), you need to understand the privacy and data security ramifications of any marketing you're doing to your targeted end user group in a way that complies with the FCC and local state regulations. Understandably, hiring an outside counsel with a $500-800/hourly rate may be prohibitive to early-stage start-ups for work that does not require specialized expertise. You may want to consider hiring a consulting attorney who has experience of working in-house and can deliver generalist services in an efficient manner and on a fixed fee arrangement.