Yes, a Cleric can dual to a Ranger, if your character meets the following stat requirements:
STR 17
DEX 17
CON17
INT 3
WIS 17
CHA 3
Here are my suggestions for the quests:
Chapter One: Irenicus's Dungeon (meet Imoen, Minsc, Jaheira, and Yoshimo)
Chapter Two: the Circus Quest (pick up Aerie if you want her in your party)
meet Gaelan
get some potions, rob the town blind, and find a fence
pick up the NPCs you want in your party--Anomen, Nalia, Korgan, Jan, or Viconia are readily available
loot the Graveyard (don't go downstairs just yet)
meet Wellyn and/or the Paladin and the orphan
head for the Bridge District and solve the kidnapping quest
solve the Bridge District Murders
fight the street thugs you run into
go to the Copper Coronet and accept Nalia's quest
come back to the Copper Coronet and free all of the slaves
go to the Docks District and do Renal's quest (meet Edwin)
now do a major quest--I recommend the Unseeing Eye/Rift Device quest (be prepared for beholders and undead creatures)
(you'll run into a few sidequests along the way, such as the Sea Troll, as well as Keldorn and possibly Haer'Dalis)
do the Temple quests (Sir Sarles, etc.)
now do the labyrinth under the Graveyard District (and/or Korgan's quest and Edwin's quest)
next major quest--Umar Hills (meet Valygar and Mazzy)
now decide whether you want to start Chapter Three or do more quests in Chapter Two
The remaining quests, in no particular order (you can try some of them any time you feel like it), include:
Den of the Seven Vales
The Fallen Paladins
City Gates lich, Elemental Lich, Shade Lich
The Twisted Rune
The Guarded Compound
Chapter Three: the Guild War (fight Kangaxx when you acquire the Mace of Disruption and his assorted parts)
Chapters Four and Five: Spellhold/Sahuagin City/Underdark
Trademeet/Druid Grove
Astral Prison (make sure you have some +3 weapons)
Note: you can meet the tollkeepers and Mekrath a lot earlier in the Temple Sewers
Planar Sphere (not as hard as Windspear Hills IMO)
Windspear Hills (probably the hardest quest you can do in Chapter Two)
The Sewer Key "quest"
Chapter Six: Rhynn Lanthorn
Forest of Tethir
Chapter Seven: Suldanessellar
I don't do everything strictly in that order, but it's a rough guide. Sometimes it just depends on which stronghold I want or which NPCs I have in my party, or it just depends on what I feel like doing at the time. But the first few quests I suggested ought to get you started, and you can go from there.
Have fun.
