The knowledge to read and write hieroglyphs was lost by 450 CE, and would remain so until the 1820s, when the Rosetta Stone was deciphered. It contains three parallel scripts – hieroglyphic, demotic, and Greek. The hieratic (priestly) and demotic (popular) scripts were more suited than hieroglyphs for use on papyrus, and existed alongside the other forms, especially in monumental and other formal writing.
Egyptian hieroglyphs consist of three kinds of glyphs:
As the hieroglyphs contain no vowels (as such), an "e" is generally inserted between the consonants to form readable words.
Translating hieroglyphs is not done directly, instead we first need to convert the hieroglyphs into readable alphabetic script. This is known as transliteration. Transliteration however use letters not normally present on keyboards:
These are not normal alphabetic characters, and as such there is no easy way to write them. Manuel de Codage (MdC), which is a standarized system for transliteration of hieroglyphic texts on computers makes this much simpler, by converting the characters above and substituting them with normal alphabetic characters.
Gardiner's Sign List is a comprehensive list of commonly used hieroglyphs, the de facto standard in Egyptology. Manuel de Codage incorporate Gardiner's list to reference specific hieroglyphs, ordered into categories for birds, occupations etc.
The hieroglyph for the sun, is part of Gardiner category N which relates to the sky, earth and water. It is designated N5, and is transcribed as ra.
As hieroglyphs, unlike alphabetic scripts, can be placed above eachother, or form groups of signs, Manuel de Codage also incorporates features to change size, orientation, color and placement of signs. This is necessary to be able to place the signs exactly in their correct position in relation to eachother.
Transliteration → nṯr-nfr-zꜢ-rꜤ-imn-ḥtp-Ꜥnḫ-wḏꜣ-snb
Transcription → netjer-nefer za-Ra imn-Htp ankh wedja seneb
Translation → The Good God, Son of Ra, Amenhotep, Life, Prosperity and Health
Manuel de Codage is more than just transliteration, and the complete text looks like this:
Manuel de Codage → nTr-nfr-zA&ra-<-i-mn:n-Htp:t*p->-anx-DA-s
Gardiner numbers → R8-F35-G39&N5-<-M17-Y5:N35-R4:X1*Q3->-S34-U28-S29
Amenhotep is transliterated imn-ḥtp, but written in MdC, the text is i-m:n-Htp:t*p. This is because MdC preserves position of individual signs. Furthermore, MdC can be written with alphabetic characters, and, using Gardiner's sign list, or a mix of both (example: R4:t*p is valid.)
The colon ( : ) and the asterisk ( * ) modifies the placement of signs or grouped signs. Link to the documentation can be found below.
I recommend JSesh Hieroglyphic Editor by Serge Rosmorduc, which, in my opinion, is the best editor to use for hieroglyphic texts of any kind. It is available for Windows, Linux and OSX and is completely free! You can even copy and paste the hieroglyphs straight into your Word documents, or, export them as JPG, PNG or SVG files or many other formats.
The first printed version of MdC was published in 1988, which at best can be considered the stone age of computing. A slightly altered version of MdC was published online in 1997 at Utrecht University Centre of Computer-aided Egyptological Research (CCER), a project which no longer exists, though the Internet Archive have snapshots of the page from 2001 here. A copy of the page can be found here, and if that vanishes too, it is archived here.
Manuel de Codage is far from perfect however, there are a number of minor annoyances that has been rectified in an updated specification called the Revised Encoding Scheme for hieroglyphic (RES) which has been under (stalled?) development since 2002, but I have found no indication that it has been accepted as the "new" standard. The documentation can be found at The RES-project.
If you are interested in learning to read hieroglyphs, an excellent place to start is Manley's Egyptian Hieroglyphs for Complete Beginners. It will give you a peek into hieroglyphics, to see if learning to read hieroglyphs is really something you want to do. It is not for the faint-hearted, it will require much time to study. The books are listed in in order of difficulty, each step becoming more difficult, but also more detailed and illuminating. The last two volumes are purely academic work, and require a good understanding of hieroglyphics, i.e. a much harder read.