I would buy a bottle of cheap whiskey for $24 and get drunk. You need at least $250 (but I recommend $2.500 or $25.000) to start doing something.
buy a domain and create a blog with your interesting niche. and then promote it in free time{ i am guessing you have too much time as you are looks newbie} and after some time put it in marketplace to be sale or start selling links
this summary: 1. buy domain 2. create a website 3. make autoblog 4. make money from ads 5. buy some drinks
Honestly, I would go get more. You definitely do not want to have all your eggs in one basket, and although $25 is actually a lot in the internet world as a startup (well, relatively - it's a domain name and a few months hosting, or more domain names and less hosting), your risks are greater when your portfolio is not diversified. In general, I would advise to do something you are passionate about, as that will yield the best results at least in terms of fulfillment, and it will definitely influence how willing you are to putting the necessary time into a project, that will turn it into a cash cow (unless you strike it lucky either way). Specifically, I would say do more of what you did to get that $25, or find out if you have some skills to offer people (look in the BST forums, especially Services) and grow that initial investment (or find an investor) until you can fund something you plan, or fund multiple things that you plan. There is relatively nothing wrong with starting say a blog, minisite or something similar with that amount of money, or even pinching it and using it to get your own unique idea out there, but your time will likely be spent promoting it or developing it, and so if it is your one source of focus, even if it does well, if it is not properly monetized (which is likely, since you seem to be new at this) you may have some success, then all of a sudden run out of funds to host it when it gets a bit more popular. If you haven't an idea already of what you want to do, I say keep saving money until you have been a bit more around the bush in terms of experiencing what you have to offer, as that will give you a better idea of what you would like to offer. Good luck.
Buy domain ($1.99 Yahoo Small Business), free hosting ($0), Sign-up for free Google ads account ($0 for $25 credits), Take me to lunch ($23.01)
I will buy some old stamps then I bury it in backyard for 30 years. After that I can sell it for 10x original prize.