I also do raised beds for everything even flowers. You would guess we live in a stone quary if you tried to dig here, what a mess. We have a manufactored homes place in town that has a scarp dumpster that is the size of a rig trailer. That's where I got all my wood for my garden beds for free. And if you are looking to do raised beds its always looking into if you have such a place in your area.
I made mine 1 1/2 wide x 10 inches deep and then depending on what was to be planted in the bed that is how long I made it. Things we eat more of got longer beds then things we only wanted a few of. Now for squash and cucs or zucs I did 5x5 ft beds but after seeing my squash plants today after the recent rains I think I should have made them bigger.
I place a thick layer of newspaper on the ground before I fill the bed, helps alittle with weeds. If its a bed I am not filling right away I top it with about 4-5 inches of grass clippings. Most of my beds I fill with pure compost I buy from a local farm/ greenhouse by the ton. It's actually cheaper then if you go to the store and buy it by the bag. If it is a bed that has topsoil in it also I add a good 4 inches of compost to it each spring and mix it in good before I plant. I also get horse manure from a local farm in the spring. Between the beds I put a good think layer of newspaper and then 3 inches of mulch. I use the stuff from a local tree trimmers. It is not a fancy or uniform in size most times but it's free and you can't beat that right.
Also you can put a layer of newspaper down around things like peppers and tomato,s pretty much anything that is on a stock and put a layer of grass clippings on the newspaper. This makes weeding pretty much unnessary. This works really well around raspberries too! Then in the fall just till the papers and all in and it composts up really nicely.
When it comes to plants vs seeds , I use both. I like alot of heirloom verities most of which I have to order via catalog and have the seeds shipped in cause I can not find them else where. But there are certain things I by plants of every year cause it is easier and I get crops off them sooner that way. tomatos, kalarobies, cabbage, and peppers are deffenit plant buys for me every year. Beats, squash, cucs, zucs, beans, lettus, naturiums, parshnips melons and some others rare things I have to order in are always seeds. My suggestion is if you have a short growing season get more plants then seeds if you have an average length season or just have things you want early buy both.
My two biggest things I push are....
compost, compost, compost! Compost is black gold and if you are going to garden you should undoubtly compost.
And soaker hoses or dripline.
I have a rain barrel I made out of recycled plastic drums at ever eve spout on our property even the chicken coop! I have found that even a 45gal barrel will run a 3/4inch soaker hose up to 100ft with no problems. ( just make sure to put them up on blocks at least two blocks off the ground or bed level for proper pressure) And to flush them once a month with a reagular hose hook up to clean pollin and such in them out. These are great for places that have dry spells or streaches were it rains for a week strait and then does not rain for the next month once. Just make sure you put something like mosquito dunks in them so you don't have to worry about mosquitos in them.
Hope these tips help and happy gardening