Learn then selling guidelines. Each marketplace has guidelines that define what you can and cannot sell. State and federal laws also impact what items are prohibited. In general, you cannot sell alcohol, weapons, service contracts, animals or event tickets. Also, while not always prohibited, you may find restrictions on how you can sell items in some categories, such as art, gift cards and coupons. eBay, Craigslist and Amazon publish these guidelines on their websites.
Check with your local bank to see if they're giving away cash bonuses for opening up accounts. Banks run promotions like this all the time, so grab some real cash quickly if you're in need. It won't break the bank (no pun intended) but it will give you a quick $50 or $100 -- maybe even more -- when you really need it. You might need to deposit a minimum amount of cash (usually in the thousands) in order to qualify for these types of accounts (but not always).
You may have noticed in my overview of the Amazon Associates site that I left out the mention of the plugin they built for WordPress. That’s because the plugin doesn’t work (at least not well). Luckily, the Amazon Auto Links plugin will simplify the process of finding new and relevant products to promote and creating affiliate links to them--all from within WordPress.
These ways of making extra money cover a wide range in terms of compensation and prestige. Check out the options to see what could work for you, keeping tabs on a projected per-hour rate so you can see what would be worth your time. The list is loosely arranged by 1. jobs requiring more skill or expertise, 2. gigs needing less and 3. things you can sell. And if you think of any good options I missed, please let me know in the comments.