Oh I am a total frugal gardener!
Tips on rain barrels. Depends on what you are doing. I like to grab "buckets" at resturant that are throwing their buckets in the trash. they are usually food grade AND they make great containers for container gardening when you clean them.
I have also used BIG barrels from those spray car washes. If you ask the manager or owner, what do they do with the barrels of detergent when they are empty they usually say they sell or throw them away and you can get them for a song. These are not food grade, but if it just holding water from rain so you can water your plants (flowers only) these are great! They go for 10-20 dollars and can be 20 to 55 gallons per barrel and they come with a lid most of the time! All you need to do is get the soap out.
Use plastic spoons instead of knives for plant naming as the knives have been known to cut you. Yes, I have cut myself on a plastic knife!
Raised beds can be easy if you have nice round yet flat river rocks and cement! It is cheaper in the long run, can last 10-50 yrs longer and won't cost an arm and a leg to make.
Easy to build PVC hot houses are easy and there is a free PVC hot house and a blog about how to make them.
You can also go look up Habitat for Humanity and see if they have old windows and build a glass greenhouse. I am thinking about doing that actually.
Also, join a gardening club as many gardeners love to "trade" ideas as well as many gardeners like myself, over grow seedlings and we usually have a swap in the spring.