Raise bed soil -You can buy it premixed, but it is usually more expense this way. I use the following and it is similar to
Mel’s Mix
Soil Mix:
Peat Moss ¼
Vermiculite or Perlite ¼
Mixed Source Compost ½ (use 3 or 4 different types of compost)
Amendments per 3’x8’ bed
Worm Castings 2lb (Cheap at Costco right now)
Azomite 2lb (Get a 10lb bag on Amazon, this adds a lot of micronutrients)
Additional info:
Raise beds are fine at about 8” deep. If you do them on bare ground, remove the sod if possible first. Put a layer of clean cardboard down and stab holes in throughout with a knife. This will allow drainage, helps hold worms and moisture.
Tomato Plants: you will want to add calcium to avoid blossom rot. Get a cheap bottle of calcium supplement pills. When the tomatoes start to produce, break 2 pills in half and bury spread out over each plants roots. This will add a clean source of calcium. You may need to add 1 or 2 more pills late season.
Do not use pressure treated or tar soaked wood, the toxins will get into your veggies. You can use most wood types, but cedar is the best. You can also use these
metal beds.
If you use a deep bed, like a horse trough, put old logs in the bottom to take up space. This will save money and will slowly feed you plants. Do not use high sap or resin woods.
Once your bed is full of soil and ready to plant, you can cover with landscape fabric. Cut holes to plant your veggies, then put plain (undyed hardwood) mulch to cover the fabric like you would in a flower bed. This will help hold moisture so you can water less and it will keep unwanted weeds out. This is optional, but I find it helps a lot with moisture retention and helps prevent the spread of yellow leaf.
Read through the square foot gardening site. There should be a guide for how close you can space your plants. It is much closer than in a regular garden.
Learn to properly compost. This will help you in the coming years with topping off your raisebeds to replenish them.
This isn't the only way to garden, its just what I have found that works for me.