Investing is a key way to build long-term wealth, made easier by zero-commission online brokerages and low-fee robo-advisors. Before investing, ensure an emergency fund, pay off high-interest debt, and assess risk tolerance. Starting with tax-advantaged accounts like 401(k)s or IRAs is recommended. Diversified index funds and ETFs offer low-cost exposure, while passive investing generally outperforms active trading. Robo-advisors can automate portfolio management affordably.