Rice noodles are widely used in every Asian region where rice is grown and eaten. Not long ago, even here in Los Angeles, they were available in only a couple sizes and only dried. Now vast quantities of fresh noodles are produced in Los Angeles and Orange counties and every Asian market has at least one or two varieties - others have more than ten varieties. Dried are available in a dozen or so sizes as well, imported from Thailand, Vietnam and China.
The photo shows a typical form, a 2.67 ounce skein of 0.027 inch / 0.75 mm diameter "rice stick", from a bag of 6 skeins. These were made in Thailand. Caution: these must never be confused with the similar appearing bean thread noodles - the two have very different cooking properties. Read the label.
These products are generally labeled in Vietnamese, Chinese, Thai and
English, but the names I give are English and Vietnamese (accents omitted)
because the Thai and Chinese characters are uninterpretable to me.
Cooking Rice Noodles
Whether fresh or dried, rice noodles need only enough cooking to heat them up - unless you want mush, which is sometimes actually the case.
Dried: If the recipe calls for fresh, use half the weight dry. Soak in slightly warm water for at least 20 minutes if noodles are very thin, or at least an hour if thicker. They can be held in the water for hours.
Fresh: If the recipe calls for dry, use twice the weight in fresh. Separate the noodles well while still cool - there will be no time later.
Boiling: Both fresh and soaked dry rice noodles need only a moment in boiling water if thin, and barely longer if thick. The way I do this is to have a strainer over a heatproof bowl or pot, drop the noodles into the boiling water, then immediately dump them out through the strainer. Water in the catch bowl can be returned to the pot if you need to do more noodles. Noodles are taken immediately from the strainer to the serving dish.
Stir Fry: This is tricky because the noodles will start to stick to the pan immediately. Basically, you just stir them in with the other ingredients long enough to warm them up and coat them with sauce - then serve. Soaked dry noodles are a little easier to handle than fresh ones and thicker easier than thin.Varieties
Fresh Rice Noodle Sheets -
The photo shows uncut sheets called Rice Roll. These are very thin and coated with oil so they can be unwrapped from the bundle. Some makers sell this form as large sheets folded up, others as a stack of single sheets. In eather case they are very thin, with different brands varying in thicknesses from 0.015 to 0.02 inches. I prefer the thicker ones if I can get them.
Buying & Storing: These are intended to be purchased
and used on the day they are made, but will still be OK the following day
or a little more if unopened - then they will start to mold and get a
Dried Rice Noodles - 
Buying & Storing: These will be found in any market
serving an East or Southeast Asian community. Store in a sealed bag to
prevent entry of moths and they will last indefinitely.
Bánh Trang - Spring Roll Wrappers -
Buying & Storing: These will be found in any market serving an East or Southeast Asian community. Store in a sealed bag to prevent entry of moths and they will last indefinitely.
Cooking: These are first moistened just enough to make
them flexible. I do this either by laying them on a damp cloth and
brushing them with water or setting them on a plate full of water (one
at a time). In a few seconds they're ready to use. They are then folded
and rolled into packets which may be served as-is or deep fried depending
on the recipe used. Handling them takes a little practice.
Rice Flake - Bánh Uot, Bánh Cuôn
buying, storage and cooking considerations are exactly as for regular rice
noodles described above.
Rice Noodle - Fine - Bun Que Lam -
Rice Ovals - [336, Rice Ovalettes, Rice
Cake; Nian Gao (China); Dduk (Korea)]
Originally developed in Ningbo in Zhejiang, China, these are now
very popular through China, and especially Korea. They are often used
in stir fries and soups. They are available fresh, dried, and, most
commonly semi-dried in vacuum packs, refrigerated or frozen. The
semi-dried are usually simmered for about 10 minutes to prepare them for
stir fry, the fresh several minutes less. The dried needs to be soaked
over night, then cooked like the semi-dried. The photo specimens,
semi-dried, made in USA, were typically 1.9 inches long, 1 inch across
and 0.19 inch thick, cut diagonally from a 1 inch diameter cylindar.
Sweet Rice, Salt, Water, Wheat Starch (wheat starch is gluten free, but
versions without that ingredient can be had).
Rice Cake Sticks -
[345, Tteokguk-yong-tteok (Korea)]
These are quite popular in Korea, where they are made up with a
mild chili sauce and sold by street vendors as a snack. The photo
specimens were 2 inches long and 1/2 inch diameter, purchased from a
Korean market in Los Angeles, refrigerated in a 23 ounce vacuum packed
bag. Ingred: Rice, Salt, Water.
Fresh Rice Noodles - precut
Rach Gia - Cheesecloth Noodles
I'm not sure yet just how this one is used, officially, but in one of my experiments I deep fried it to produce something very like vegetarian pork rinds.