1. I want to write my name in Runes; how do I know what sound each Rune makes?
2. Why did the Runes not become a more prominent writing system, like the Latin alphabet?
To help answer the first question, I created a chart showing the sounds assigned to each Rune. (It is similar to the chart I created for Rune meanings.) There are a few interesting Rune sounds to take note of. For example, Eihwaz, which I wrote about two weeks ago, produces an ei combination sound. Ingwaz, joins the sound of two consonants - ng. Although Wunjo looks like our Latin p, it makes the w sound. And, Jera, although it is j, its sound leans more towards y.
One of the Runes I didn't mention above, but which has a duel sound is Thurisaz. This letter actually evolved in Icelandic as the letter thorn and it makes the th sound as in thumb or Thor. So, if your name is Theodore, the first two letters would be combine into one. It would look like this:
Now for the second question. There are multiple reasons why Runes never became an alphabet like the Latin one we use today and what I provide here is only a summarized overview. For starters, Runes were made to be carved and their angular shape was easiest to carve into the resources available - wood, bone and antlers - with Runestone engravings coming later, but maintaining the angular aspect. Because they were designed to be carved, the complicated process used to create such things as papyrus, parchment or vellum was not needed, nor was the requirement to make ink or quills. Instead, Germanic people used their knives and carved messages onto available resources. Beyond the requisite equipment, there were no grammar or writing rules; Rune carvers spelled things phonetically, the way they sounded to them. Rune shapes varied regionally and things were not always written from left two right. Words, phrases, even sentences could be written right to left and there are boustrophedonic examples as well, where one line reads from left to right and the next lines reads from right to left. There are more reasons, but this gives you a sense of some of the basic issues around why the Runes never became an alphabet like the Latin one. The Viking Answer Lady provides some good insight into this issue as well.
If you have more questions about the Runes, whether it's for writing or using them as an oracle, let me know. I am happy to help.