1. A quarter inch seam allowance is standard, and most sewing machine have an optional (or included) foot that is a quarter inch foot. I have one, and I just run the edge of my fabric right along the edge of the foot and Perfect (or close enough). I love my quarter inch foot.
2. You need to press the block as you make it. Some people press the seams open so it will lie flatter, some people press the seam allowance under the darker fabric so it won't show through, and some people only care about pressing it to the side that makes it look best when you flip it over to the front -- I'm one of those. You can finger press if you like but a good old ironing board and an iron (possibly extra spray starch) make life easier.
3. Rotary cutters are necessary. How pioneer women ever did without these pizza-slicer-like tools is beyond me. I like the occasional template but for squares and triangles (especially with machine strip-piecing) it's a rotary cutter every time. That means a cutting mat and an omni-grid ruler too. Trust me it's worth investing in one of these if you plan on making more than one quilt ever.
4. Buy thin pins. To be honest I rarely pin anywhere but the points of stars and triangles, but when I do I pin it's because I want my points to (mostly) match properly. Thin pins are less likely to shift the fabric as you pin, meaning the points are more likely to stay put. Thin pins are also less likely to break the sewing machine needle if you sew over them -- and you know that's not just speculation. If you can find glass headed dressmakers pins get those, they don't melt when you iron them. You might not think that's an important feature but, well, I do.
5. Use grey thread. I talked about that already here.
6. Most quilts use cotton fabrics, which come on bolts 45 inches wide and sold by the yard (or quarter yard). Get woven fabrics, not knits. Knits will stretch and ruffle and bumfle. And you really do want to use a natural fiber, I've made some wool quilts and quite a few cotton quilts and I'd be tempted by linens and silks -- but poly-cottons, double knits, and the like are a pain to sew through. They'll blunt your needle faster, and polyesters don't hold a crease (you'll never get those seams to lie flat).
7. Cotton fabric does shrinks the first time it's washed, a subject I sort of already talked about here.
8. When in doubt go for high contrast. Lighter lights and darker darks and brighter accent colors will stand out against each other more making the quilt block more highly graphic. If you're going to spend several hours (or years) cutting fabric into little bits and sewing it back together again you want that pattern to show up. (I'll talk more about color theory some other time.)
9. There are different ways to finish a quilt, you can use a quilting stitches to secure the three layers (top, batting, and backing) or tie it. I use pearl cottons or tapestry yarns instead of embroidery floss to tie a quilt, I like the texture better. And those raw edges can be hidden envelope style, or with binding, or by simply folding one edge over the other. I've used all three methods and I think I prefer the latter.
Up Next -- Nine-Patch Know-How