The orthography of Swedish is pretty similar to that of German. Swedish uses your basic 26-letter Latin alphabet like English, with the addition of the letters å, ä and ö. The latter two have values close to German, and it also shares with German the practice of using double consonants to show the preceding vowel is short and only one consonant to show the preceding vowel is long. Like in German, and unlike in Dutch, in Swedish a word can end with two consonant letters and vowel letters are not doubled to show length; and because of this a word like bok has a long O, while a word like mitt has a short I. Swedish spelling also shares with English and German the use of CK as the doubled version of K; and with German and Dutch the use of J for i̯ / j.
W, Q, Z, the digraph CH and C are rarely used outside of proper names and loanwords, except for the word och – more on C later. The pronunciations of the letters b d f h l m n p s t v x and the digraph ng are pretty self explanatory if you already know English. Swedish, like English and unlike German and Dutch, does not have syllable final devoicing of consonants, and like English and German but unlike standard Dutch, aspirates p t k in certain environments.
The pronunciation of R should not be difficult to anyone who can already pronounce Spanish – it can either be pronounced r or ɾ depending on its position in the word. The distribution of these realizations is very reminiscent of Spanish. Like in Spanish, they are only contrastive intervocalically. One of the interesting things about R in Swedish is that the clusters rd rl rn rs rt, in which you’d expect ɾd ɾl ɾn ɾs ɾt, simplify to the retroflex consonants ɖ ɭ ɳ ʂ ʈ. If you’re learning Swedish and the thought of this is already giving you a headache, you could always learn the Scanian accent instead, which pronounces R as ʁ, otherwise known as the French R.
Let’s move on to the really interesting part as far as I’m concerned: vowels.