I have been using Vanguard LS 80 for a while with excellent returns. I strongly recommend looking at sites such as monevator and reading about investment strategies.
Passive investment plus an ETF like VLS80 is simple and effective (historically).
In answer to the initial question, there has been a recent downturn in the market and with uncharted territory ahead I would not put my money into s&s if I needed it within 3 to 5 years (house purchase). It all depends on your tolerance to risk